LOCKING UNIT FOR ONE SHAPING MACHINE

Abstract

Clamping unit for a molding machine, in particular for an injection-molding machine, with a machine frame, an end plate arranged on the machine frame, a platen movably mounted on the machine frame, a stationary platen arranged on the machine frame, at least two, in particular four, tie bars, via which a clamping force can be transmitted, and a mold height adjustment apparatus for adjusting the mold height for a molding tool which can be or is fitted on the platen, wherein the mold height adjustment apparatus has

i. a rotatable adjustment element gripping on at least one tie bar,
ii. a drive device for rotating the rotatable adjustment element and
iii. a locking device for securing the rotatable adjustment element against a rotational movement relative to the at least one tie bar.

Claims

1. A clamping unit for a molding machine, in particular for an injection-molding machine, comprising: a machine frame, an end plate arranged on the machine frame, a platen movably mounted on the machine frame, a stationary platen arranged on the machine frame, at least two, in particular four, tie bars, via which a clamping force can be transmitted, and a mold height adjustment apparatus for adjusting the mold height for a molding tool which can be or is fitted on the platen, wherein the mold height adjustment apparatus includes: i. a rotatable adjustment element gripping on at least one tie bar, ii. a drive device for rotating the rotatable adjustment element and iii. a locking device for securing the rotatable adjustment element against a rotational movement relative to the at least one tie bar.

2. The clamping unit according to claim 1, wherein a platen drive mechanism, preferably a toggle lever mechanism, for moving the movable platen between an open position of the molding tool and a closed position of the molding tool is arranged between the end plate and the movable platen.

3. The clamping unit according to claim 1, wherein the rotatable adjustment element is formed as an adjustment nut with an internal thread, wherein this internal thread correspondingly grips on an external thread formed on at least one tie bar.

4. The clamping unit according to claim 1, wherein the rotatable adjustment element has a gearwheel-shaped outer surface, wherein this gearwheel-shaped outer surface meshes with a gear rim of the drive device.

5. The clamping unit according to claim 1, wherein the locking device is formed as an electrically actuatable braking device.

6. The clamping unit according to claim 5, wherein this electrically actuatable braking device has a brake disk secured on the rotatable adjustment element and brake shoes, and in a braking position the brake shoes secure the brake disk between the brake shoes against a rotational movement.

7. The clamping unit according to claim 6, wherein the brake shoes are fitted on the end plate via a support, wherein the brake shoes are mounted movably via an electrical drive unit relative to the support.

8. The clamping unit according to claim 1, wherein the locking device is formed as a hydraulically actuatable braking device.

9. The clamping unit according to claim 8, wherein this hydraulically actuatable braking device has a flange element which is fitted on the end plate and which surrounds the rotatable adjustment element at least in areas, an annular pressure chamber, which is formed between an outer surface of the adjustment element and an inner surface of the flange element and is delimited by two seals, a feed channel formed in the flange element for a hydraulic pressure medium into the annular pressure chamber and a braking surface, via which the adjustment element contacts the end plate, wherein pressure, preferably between 20 and 80 bar, can be applied to the adjustment element by the hydraulically actuatable braking device via the hydraulic pressure medium in the pressure chamber, with the result that the braking surface of the adjustment element is pressed against the end plate and the adjustment element is secured against a rotational movement by the friction between adjustment element and end plate.

10. The clamping unit according to claim 9, wherein the adjustment element has a wear ring, wherein the braking surface is formed on this wear ring.

11. The clamping unit according to claim 9, wherein an annular groove is formed on the inner surface of the flange element which inner surface delimits the pressure chamber.

12. A clamping unit for a molding machine, in particular for an injection-molding machine, comprising: a machine frame, a platen movably mounted on the machine frame, a stationary platen arranged on the machine frame, a hydraulic mold height adjustment apparatus for adjusting the mold height for a molding tool which can be or is fitted on the platen, a platen drive mechanism for moving the movable platen relative to the stationary platen and a lubricant system for supplying lubricating points of the platen drive mechanism, wherein the lubricant system and the hydraulic mold height adjustment apparatus have a common pump for feeding pressurized lubricant to the lubricant system and/or to the mold height adjustment apparatus.

13. The clamping unit according to claim 12, wherein the hydraulic mold height adjustment apparatus is or can be fluidically connected to the lubricant system and pressurized lubricant of the lubricant system can be fed to the hydraulic mold height adjustment apparatus by the pump.

14. The clamping unit according to claim 12, wherein a locking device for securing a rotatable adjustment element of the mold height adjustment apparatus against a rotational movement is fluidically connected to the lubricant system.

15. The clamping unit according to claim 12, wherein an axial play of the rotatable adjustment element of the mold height adjustment apparatus in the flange element can be eliminated by a pressing of the rotatable adjustment element of the mold height adjustment apparatus against the end plate.

16. A molding machine comprising an injection unit and the clamping unit according to claim 1.

17. The molding machine according to claim 16, wherein a common control or regulating unit for controlling or regulating the mold height adjustment apparatus and the platen drive mechanism, and optionally the pump, is provided.

Description

[0043] Further details and advantages of the present invention are explained in more detail below with the aid of the description of the figures with reference to the embodiment examples represented in the drawings. There are shown in:

[0044] FIG. 1, schematically, a molding machine in an open position in the case of a small mold height,

[0045] FIG. 2, schematically, a molding machine in an open position in the case of a larger mold height of the molding tool,

[0046] FIGS. 3 to 6 various views of a mold height adjustment apparatus with an electrically actuatable braking device,

[0047] FIGS. 7 to 10 various views of a mold height adjustment apparatus with a hydraulically actuatable braking device and

[0048] FIG. 11, schematically, a lubricant system with lubricating points and a mold height adjustment apparatus.

[0049] FIG. 1 schematically shows a molding machine 2 in the form of a 3-plate injection-molding machine. However, the molding machine 2 can also be a molding press or transfer-molding press.

[0050] Specifically, the molding machine 2 has an injection unit 27, only indicated schematically, and a clamping unit 1, represented in more detail. The stationary platen 6 is fastened to a machine frame 3 of this clamping unit 1. The movable platen 5 and the end plate 4 are movably mounted on the frame 3 via the guide 28.

[0051] By way of example, a lubricating point 25 in the form of a toggle lever bolt is marked.

[0052] In addition, tie bars 7 are provided, along which the relative movements of the movable platen 5 and the end plate 4 are effected. A relative movement between the end plate 4 and the movable platen 5 is effected via a suitable platen drive mechanism 10. In this case, this is formed as a toggle lever mechanism.

[0053] If other mold halves of a molding tool 9 are now clamped against the platens 5 and 6, it is usually necessary also to carry out an adaptation to the different mold height that usually exists then. In other words, in an open position of the molding tool, as shown in FIGS. 1 and 2, the distance between the movable platen 5 and the stationary platen 6 is altered correspondingly.

[0054] This alteration or adaptation is effected via the mold height adjustment apparatuses 8, only indicated schematically in FIGS. 1 and 2. In principle, only one such mold height adjustment apparatus 8 has to be provided. In the case of a 3-plate machine, as represented in FIGS. 1 and 2, this mold height adjustment apparatus 8 can be arranged or formed in or on the end plate 4.

[0055] A movement of the end plate 4, lever and the movable platen 5 relative to the machine frame 3 is triggered via this mold height adjustment apparatus 8. The stationary platen 6 is firmly connected to the machine frame 3, thus a relative adjustment between the two platens 5 and 6 is also always effected.

[0056] An end plate 4 with a mold height adjustment apparatus 8 is represented in perspective in FIG. 3, wherein this mold height adjustment apparatus 8 is formed as an electrically actuatable braking device 15.

[0057] The mold height adjustment apparatus 8 has four rotatable adjustment elements 8.1, each gripping on a tie bar 7, a drive device 8.2 for rotating the rotatable adjustment elements 8.1 and four locking devices 8.3 for securing the rotatable adjustment elements 8.1 against a rotational movement relative to the respective tie bar 7.

[0058] The drive device 8.2 has an electric motor 29, which rotatably drives the gear rim 14 via a rotatable pinion. This gear rim 14 meshes, with its teeth formed on the outer surface, on the gearwheel-shaped outer surfaces 13 of the adjustment elements 8.1 (these are concealed by the brake disks 16 in the representation according to FIG. 3).

[0059] The locking devices 8.3 represented in FIG. 3 in the form of electrically actuatable braking devices 15 in each case have a brake disk 16 secured on the rotatable adjustment element 8.1 and brake shoes 17. In a braking position, the brake disks 16 are secured between the brake shoes 17 against a rotational movement.

[0060] The brake shoes 17 are fitted on the end plate 4 via a support 18, wherein the brake shoes 17 are mounted movable via an electrical drive unit relative to the support 18.

[0061] A front view of the end plate 4 together with mold height adjustment apparatus 8 according to FIG. 3 is represented in FIG. 4. The section line A-A is marked in this FIG. 4.

[0062] FIG. 5 shows the upper area of the cross section according to the section line A-A. It can easily be seen that the rotatable adjustment element 8.1 is formed as an adjustment nut 30 with an internal thread 11, wherein this internal thread 11 correspondingly grips on an external thread 12 formed on at least one tie bar 7.

[0063] The adjustment element 8.1 is rotatably mounted between the flange element 20 secured on the end plate 4 and the end plate 4. The gearwheel-shaped outer surface 13 which is formed on the adjustment element 8.1 and which is connected to the gear rim 14 in a movement-transmitting manner can be seen in this FIG. 5.

[0064] The two brake shoes 17 movable relative to each other and the brake disk 16 which can be wedged between these brake shoes 17 can also be easily seen in the cross section according to FIG. 5.

[0065] FIG. 6 shows a further perspective of the mold height adjustment apparatus 8 with an electrically actuatable braking device 15, wherein the tie bars 7 are not visible. The teeth, only indicated schematically, of the gear rim 14 and of the gearwheel-shaped outer surface 13 of the rotatable adjustment element 8.1 can be seen.

[0066] In FIGS. 7 to 10, the locking device 8.3 is formed as a hydraulically actuatable braking device 19.

[0067] FIG. 7 shows the end plate 4 with tie bars 7 and the mold height adjustment apparatus 8 attached on the end side in perspective. The drive device 8.1, the gear rim 14 and the adjustment element 8.1 are formed the same as in the first embodiment variant according to FIGS. 3 to 6.

[0068] The essential components of the hydraulically actuatable braking device 19 are formed in the flange elements 20, wherein details can be easily seen in FIGS. 8 to 10.

[0069] The adjustment element 8.1 is formed multi-part in the perspective cross section according to FIG. 8. This adjustment element 8.1 has the adjustment nut 30 with the internal thread 11, the gearwheel 31 with the gearwheel-shaped outer surface 13 and several fastening means 32 for connecting the adjustment nuts 30 to the gearwheel 31.

[0070] The hydraulically actuatable braking device 19 has several components:

[0071] One component is a flange element 20 which is fitted on the end plate 4 and which surrounds the rotatable adjustment element 8.1 at least in areas.

[0072] A further component is an annular pressure chamber 21, which is formed between an outer surface A of the adjustment element 8.1 and an inner surface I of the flange element 20 and is delimited by two seals 22.

[0073] In addition, the braking device 19 has a feed channel 23, formed in the flange element 20, for feeding a hydraulic pressure medium into the annular pressure chamber 21 and a braking surface B, via which the adjustment element 8.1 contacts the end plate 4.

[0074] Pressure can be applied to the adjustment element 8.1 by the hydraulically actuatable braking device 19 via the hydraulic pressure medium in the pressure chamber 21. The braking surface B of the adjustment element 8.1 is thereby pressed against the end plate 4. The adjustment element 8.1 is secured against a rotational movement by the friction between adjustment element 8.1 and end plate 4.

[0075] The components of the braking device 19 are represented even larger in FIG. 9. The grooves—in this case represented empty—in which the annular seals 22 for delimiting the pressure chamber 21 are arranged can be seen.

[0076] A cross section matching the previous figures is represented in FIG. 10. The adjustment element 8.1 can have a wear ring B, wherein the braking surface B is formed on this wear ring.

[0077] In order to make a uniform pressure application possible, an annular groove (not represented) can be formed on the inner surface I of the flange element 20 delimiting the pressure chamber 21. Alternatively or additionally, an annular groove (not represented) can also be formed on the outer surface A of the adjustment element 8.1.

[0078] A lubricant system 24 is represented schematically in FIG. 11. This lubricant system 24 has a motor M and a pump 26 driven by this motor M, wherein lubricant can be drawn out of the tank T via the pump 26.

[0079] The lubricating points 25 are arranged between the switch element 33 (e.g. in the form of a manifold valve) and the pump 26. Via a switchable check valve 34, an unloading of the hydraulically actuatable braking device 19 can be effected in a further switch position of the switch element 33 (a position moved towards the right).

LIST OF REFERENCE NUMBERS

[0080] 1 clamping unit [0081] 2 molding machine [0082] 3 machine frame [0083] 4 end plate [0084] 5 movable platen [0085] 6 stationary platen [0086] 7 tie bars [0087] 8 mold height adjustment apparatus [0088] 8.1 rotatable adjustment element [0089] 8.2 drive device [0090] 8.3 locking device [0091] 9 molding tool [0092] 10 platen drive mechanism [0093] 11 internal thread [0094] 12 external thread [0095] 13 gearwheel-shaped outer surface [0096] 14 gear rim [0097] 15 electrically actuatable braking device [0098] 16 brake disk [0099] 17 brake shoes [0100] 18 support [0101] 19 hydraulically actuatable braking device [0102] 20 flange element [0103] 21 pressure chamber [0104] 22 seals [0105] 23 feed channel [0106] 24 lubricant system [0107] 25 lubricating points [0108] 26 pump [0109] 27 injection unit [0110] 28 guide [0111] 29 electric motor [0112] 30 adjustment nut [0113] 31 gearwheel [0114] 32 fastening means [0115] 33 switch element [0116] 34 switchable check valve [0117] A outer surface of the adjustment element [0118] B wear ring [0119] I inner surface of the flange element [0120] B braking surface [0121] M motor [0122] T tank