Molding method using mold structure

Abstract

A molding method includes: setting a bus bar at a first mold main body portion of a fixed mold by supporting a terminal base of a tuning-fork terminal with a terminal base receiving portion of the fixed mold in a state where the tuning-fork terminal is protruded outside a cavity formed by the first mold main body portion of the fixed mold and a second mold main body portion of a movable mold being joined together; joining the movable mold together with the fixed mold by abutting an abut step portion of the movable mold to a receiving abut step portion of the fixed mold and nipping the terminal base of the tuning-fork terminal with the terminal base receiving portion and a terminal base abut portion of the movable mold; and injecting resin into the cavity in the nipped state.

Claims

1. A molding method using a mold structure to bury a bus bar having a main body circuit unit with a tuning-fork-like tuning-fork terminal along with molding of a resin molded product with a fixed mold and a movable mold, the tuning-fork terminal comprising: a bus bar end including a terminal base; and a press fitting contact portion having a pair of nipping pieces and integrally extended from the bus bar end, the pair of nipping pieces each having an insertion opening formed at a top end side thereof for a counterpart terminal and a slit formed continuously from the insertion opening, the terminal base being a closed end of the slit, the nipping pieces mutually facing each other such that the slits of the nipping pieces mirror each other, the molding method comprising: setting the bus bar at a first mold main body portion of the fixed mold by supporting a terminal base of the tuning-fork terminal with the terminal base receiving portion of the fixed mold in a state where the pair of nipping pieces of the tuning-fork terminal is protruded outside a cavity formed by the first mold main body portion of the fixed mold and a second mold main body portion of the movable mold being joined together and where the terminal base is positioned inside the cavity; joining the movable mold together with the fixed mold by abutting an abut step portion of the movable mold to a receiving abut step portion of the fixed mold and nipping the terminal base of the tuning-fork terminal with the terminal base receiving portion and a terminal base abut portion of the movable mold, wherein the terminal base receiving portion comprises a bus bar set portion, and the terminal base is inserted into a set groove of the bus bar set portion; and injecting resin into the cavity in a nipped state in which the nipping pieces with the slits mirroring each other are protruded outside the cavity, wherein the terminal base is covered with the resin.

2. The molding method of claim 1, wherein the terminal base abut portion of the movable mold comprises a right-angle portion and the terminal base abut portion of the movable mold contacts the terminal base of the tuning-fork terminal on a top surface and a side surface of the terminal base.

3. The molding method of claim 1, wherein the terminal base in the nipped state is integrally folded from both end portions of a connection portion of the bus bar end connected to a power source side terminal plate, and wherein the injecting the resin into the cavity is performed with the terminal base folded.

4. The molding method of claim 1, wherein the terminal base in the nipped state is integrally folded at a right angle from both end portions of a connection portion of the bus bar end connected to a power source side terminal plate.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a sectional side view illustrating molding with a related mold structure.

(2) FIG. 2 is a sectional plane view illustrating molding with the related mold structure.

(3) FIG. 3 is a perspective view of a bus bar applied to a mold structure according to an embodiment of the present invention.

(4) FIG. 4A is a plane view of the bus bar illustrated in FIG. 3.

(5) FIG. 4B is a right side view of the bus bar illustrated in FIG. 3.

(6) FIG. 4C is a front view of the bus bar illustrated in FIG. 3.

(7) FIG. 5 is a perspective view illustrating a substantial part of the mold structure according to the embodiment of the present invention.

(8) FIG. 6 is a sectional view illustrating the substantial part of the mold structure.

(9) FIG. 7 is a perspective view illustrating a tuning-fork terminal of the bus bar.

(10) FIG. 8 is a perspective view illustrating a supporting state of the tuning-fork terminal at the time of molding.

(11) FIG. 9 is a perspective view illustrating the supporting state of the tuning-fork terminal at the time of molding from view of the back side of FIG. 8.

(12) FIG. 10 is a perspective view illustrating a molded electrical component.

(13) FIG. 11A is a plane view of the molded electrical component.

(14) FIG. 11B is a right side view of the molded electrical component.

(15) FIG. 11C is a front view of the molded electrical component.

(16) FIG. 12 is a perspective view of a state where a fuse is attached to the molded electrical component.

(17) FIG. 13 is a perspective view of a state where a cover is attached to the fuse part of the electrical component.

DETAILED DESCRIPTION

(18) In the following, an embodiment of the present invention will be described in detail with reference to the drawings. FIGS. 3 to 13 are an embodiment of the present invention. FIGS. 3 and 4 illustrate a bus bar. FIG. 5 is a perspective view of a substantial part of a mold structure. FIG. 6 is a sectional view of the substantial part of the mold structure. FIG. 7 is a perspective view of the bus bar. FIGS. 8 and 9 are perspective views of a supporting state of the tuning-fork terminal at the time of molding. FIGS. 10 and 11 illustrate a molded electrical component. FIGS. 12 and 13 illustrate perspective views of post-processing for the molded electrical component.

(19) As illustrated in FIGS. 3 and 4A to 4C, a bus bar 3 applied to a mold structure 1 of the present embodiment is formed by arranging a tuning-fork terminal 32 to a main body circuit unit 31. At the main body circuit unit 31, a power source side terminal plate 33 which has a power source side stud bolt hole 33a formed and a connection side terminal plate 34 which has a connection bolt hole 34a formed are connected with a fusible body portion 35. The fusible body portion 35 melts when excessive current flows from the power source side and a load connected to the connection side terminal plate 34 is protected owing to the melting.

(20) The tuning-fork terminal 32 is arranged in a state as being connected to the power source side terminal plate 33 side. As illustrated in FIGS. 4A to 4C and 7, the tuning-fork terminal 32 includes a bus bar end 37 which is connected to the power source side terminal plate 33 and a press fitting contact portion 38 arranged in an extended manner from the bus bar end 37. The bus bar end 37 is formed with a horizontally long connection portion 39 connected to the power source side terminal plate 33 and a right-left pair of terminal bases 40 integrally folded at a right angle from the both end portions of the connection portion 39 in the length direction. The horizontally long connection portion 39 is cut off before or after molding the bus bar 3.

(21) The press fitting contact portion 38 includes a pair of nipping pieces 41 linearly arranged in an extended manner from the respective terminal bases 40. The pair of nipping pieces 41 extends in parallel as mutually opposing as well as the respective terminal bases 40. The respective nipping pieces 41 have a slit 42 extended in the length direction and the extended end portion of the slit 42 is opened to be an insertion opening 43. A fuse 45 (see FIG. 12) which is a counterpart terminal is inserted into the insertion opening 43 and the nipping pieces 41 pressure-contact to the inserted fuse 45 from upper and lower sides. An electrical connecting between the tuning-fork terminal 32 (bus bar 3) and the fuse 45 is performed owing to the pressing and contacting.

(22) The mold structure 1 of the present embodiment integrally buries the abovementioned bus bar 3 with molding of a resin molded product of a fixed mold 4 (lower mold) and a movable mold 5 (upper mold). A mold main body portion (not illustrated) to set the main body circuit unit 31 of the bus bar 3 is formed at the fixed mold 4. At the movable mold 5, a mold main body portion (not illustrated) to form a cavity for molding of the resin molded product together with the mold main body portion of the fixed mold 4 is formed as opposing to the mold main body portion of the fixed mold 4. The main body circuit unit 31 of the bus bar 3 is set in the mold main body portions of the molds 4, 5 and resin is injected into the cavity after mold joining (mold clamping). Thus, the main body circuit unit 31 is integrally buried with the resin.

(23) FIGS. 5, 6, 8, and 9 illustrate a set structure of the fixed mold 4 and the movable mold 5 against the tuning-fork terminal 32.

(24) As illustrated in FIGS. 5 and 9, a pair of bus bar set portions 11 to set the terminal bases 40 of the tuning-fork terminal 32 is formed at a set part of the tuning-fork terminal 32 at the fixed mold 4. Each bus bar set portion 11 has a set groove 11a which is opened upward to have the terminal bases 40 inserted. Positioning installation of the tuning-fork terminal 32 against the fixed mold 4 is performed by inserting the terminal base 40 into the set groove 11a. The bus bar set portion 11 is formed at a position in the vicinity of an outer circumferential wall 12 (burr cut portion) of the fixed mold 4. According to the present embodiment, setting of the terminal base 40 to the bus bar set portion 11 is performed as having the pair of nipping pieces 41 of the tuning-fork terminal 32 protruded to the outside of the fixed mold 4 and the movable mold 5, as illustrated in FIGS. 5, 8, and 9.

(25) The nipping pieces 41 of the tuning-fork terminal 32 are located at the movable mold 5 side in FIG. 5. However, FIG. 5 is for illustrative purposes to show relation of a later mentioned terminal base abut portion 17 and nipping pieces 41 and nipping pieces 41 of the tuning-fork terminal 32 are set to the bus bar set portions 11 of the fixed mold 4.

(26) The bus bar set portions 11 are formed in the fixed mold 4 in a standing manner. The set groove 11a of the bus bar set portion 11 of the fixed mold 4 supports the terminal base 40 (lower face of the terminal base 40) with contacting to the terminal base 40 of the tuning-fork terminal 32.

(27) An outer circumferential face 15 (burr cut portion) which is to be the same face with the outer circumferential wall 12 of the fixed mold 4 owing to mold joining is formed at the movable mold 5 (see FIG. 8). According to the present embodiment, a window portion 19 to which the outer circumferential wall 12 of the fixed mold 4 is fit with mold joining is formed at the movable mold 5. The window portion 19 is formed in a shape being suitable for the outer circumferential wall 12 of the fixed mold 4. As the outer circumferential wall 12 of the fixed mold 4 is fitted to the window portion 19, the outer circumferential wall 15 of the movable mold 5 and the outer circumferential wall 12 of the fixed mold 4 form the same face.

(28) The terminal base abut portion 17 corresponding (opposing) to the terminal base receiving portion 13 of the fixed mold 4 is formed at the outer circumferential wall 15 of the movable mold 5. The terminal base abut portion 17 abuts to the terminal base 40 (upper face of the terminal base 40) of the tuning-fork terminal 32 supported by the terminal base receiving portion 13 (set groove 11a of the bus bar set portion 11) owing to mold joining. The terminal base 40 is nipped together with the set groove 11a owing to the abutment.

(29) As illustrated in FIG. 6, a receiving abut step portion 21 is formed at the fixed mold 4 and an abut step portion 23 corresponding to the receiving abut step portion 23 is formed at the movable mold 5. The receiving abut step portion 21 is formed by cutting out a vicinity of the bottom part of the fixed mold 4 in a plane manner and the forming position can be set at an arbitrarily position of the fixed mold 4. The abut step portion 23 is formed at the movable mold 5 corresponding to the receiving abut step portion 21. As the movable mold 5 is moved to the fixed mold 4 side and mold joining is performed, the abut step portion 23 of the movable mold 5 abuts to the receiving abut step portion 21 of the fixed mold 4. A cavity is formed between the mold main body portion of the movable mold 5 and the mold main body portion of the fixed mold 4 with the abutment. Simultaneously with the abutment, nipping of the terminal base 40 of the tuning-fork terminal 32 with the abovementioned set groove 11a and the terminal base abut portion 17 is performed.

(30) Next, molding of the mold structure according to the present embodiment will be described.

(31) The main body circuit unit 31 of the bus bar 3 is set to the mold main body portion of the fixed mold 4 in a mold opening state. At that time, for the tuning-fork terminal 32 of the bus bar 3, the terminal base 40 is inserted to the bus bar set portion 11 (set groove 11a) of the fixed mold 4 to be set. With the bus bar set portion 11 being set, the terminal base 40 of the tuning-fork terminal 32 becomes to a state to be supported by the terminal base receiving portion 13 (set groove 11a of the bus bar set portion 11) of the fixed mold 4. For such setting of the fixed mold 4 of the bus bar 3, the pair of nipping pieces 41 of the tuning-fork terminal 32 is arranged to be protruded outward of the outer circumferential wall 12 of the fixed mold 4.

(32) After setting the abovementioned bus bar 3, the movable mold 5 is approximated to the fixed mold 4 and mold joining is performed. At the time of mold joining, the terminal base 40 of the tuning-fork terminal 32 is nipped with the terminal base receiving portion 13 (bus bar set portion 11 of the set groove 11a) of the fixed mold 4 and the terminal base abut portion 17 of the movable mold 5 while the abut step portion 23 of the movable mold 5 abuts to the receiving abut step portion 21 of the fixed mold 4. Thus, the nipping pieces 41 of the tuning-fork terminal 32 are maintained in a state as being protruded to the outside of the mold main body portions of the fixed mold 4 and the movable mold 5. That is, the nipping pieces 41 of the tuning-fork terminal 32 are at a free state at the outside of the mold main body portions of the fixed mold 4 and the movable mold 5.

(33) With the terminal base 40 in a nipped state, melting resin is injected into the cavity formed with the mold main body portions of the fixed mold 4 and the movable mold 5 and cooling and hardening is performed. Thus, as illustrated in FIGS. 10 and 11, the main body circuit unit 31 of the bus bar 3 is buried in the resin molded product and an electrical component 25 which has the tuning-fork terminal 32 exposed at the outside of the resin molded product 26 such as a fusible link unit is formed. In FIGS. 10 and 11A to 11C, a stud bolt 47 is protruded upward from the resin molded product 26. Here, the stud bolt 47 is previously attached to the bus bar 3 to penetrate the connection bolt hole 34a.

(34) FIG. 12 illustrates a state where the fuse 45 is attached to the electrical component 25 as a counterpart terminal. The fuse 45 is attached to the electrical component 25 in an electrical conduction state with the bus bar 3 by being inserted into the pair of nipping pieces 41 of the tuning-fork terminal 32 exposed from the resin molded product 26. FIG. 13 illustrates a protected state of the fuse 45 as a cover 48 is fixed over the mounting part of the fuse 45.

(35) In such an embodiment, since injection of resin is performed in a state where a pair of nipping pieces 41 of the tuning-fork terminal 32 is protruded to the outside of the mold main body portion of the fixed mold 4 and movable mold 5, the nipping pieces of the tuning-fork terminal 32 are in a free state against the fixed mold 4 and the movable mold 5. Therefore, not only does the nipping pieces do not contact to the fixed mold 4 and the movable mold 5 but pressing force of the mold does not occur. Accordingly, the tuning-fork terminal 32 (nipping pieces 41) does not deform and occurrence of defective goods owing to deformation can be prevented.

(36) Since positioning of the tuning-fork terminal 32 is performed as the terminal base 40 thereof is set to the bus bar set portion 11, positioning of the tuning-fork terminal 32 against the fixed mold 4 can be performed smoothly and accurately. In this case, the terminal base 40 is fixed to the fixed mold 4 and the nipping pieces 41 at the top end side of the terminal base 40 is in a free state. Therefore, the nipping pieces 41 electrically connected to the fuse 45 do not deform.

(37) Since the resin molded product 26 is molded with the nipping pieces 41 of the tuning-fork terminal 32 protruded to the outside from the mold main body portion of the fixed mold 4 and the movable mold 5, the whole of the tuning-fork terminal 32 is not exposed from the resin molded product 26 and a part is buried in the resin molded product 26. Thus, supporting force of the resin molded product 26 against the tuning-fork terminal 32 is enlarged and strength can be applied to the tuning-fork terminal 32.

(38) In the abovementioned embodiment, the bus bar 3 having the power source side terminal plate 33 and the connection side terminal plate 34 is adopted. However, a bus bar 3 having another structure may be adopted.

(39) The abovementioned electrical component 25 is a fuse unit including a bus bar having a battery terminal or a fusible body attached to a battery terminal and a pressure-contact type fuse terminal connected to the bus bar. Here, the electrical component 25 is an example of a fuse unit (fusible link unit; fuse block) attached to a battery terminal as follows. The bus bar formed at the fusible body is molded with pressing, a pair of tuning-fork terminal connected to a fuse has one end connected to the bus bar, the other end has a terminal for external connection, the pair of tuning-fork terminal is arranged to vertically nip the fuse terminal, and the bus bar and the pair of tuning-fork terminal are molded integrally.

(40) According to the fuse unit, molding can be performed without using a slide mold and the fuse terminal is nipped and held with the tuning-fork terminal. Therefore, a fuse holder to hold the fuse 45 is unnecessarily to be separately prepared.

(41) Embodiments of the present invention are described in the above. However, the present invention is not limited to the above embodiments and various modifications can be performed.