JPH0547609Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a friction clamp type mold clamping device for a molding machine such as an injection molding machine.

[Conventional technology]

Conventionally, the following (a) or (b) have been known as friction clamp devices for molding machines.

(a) As shown in FIG. 3, a hollow double-acting piston 35 is disposed within a mold clamping cylinder 37 that is integrally provided with a movable platen 31 that is moved up and down by a mold opening/closing cylinder 33, and the hollow double-acting piston 35 is A radially elastically deformable sleeve 36 provided within the piston 35
into the tie rod 34 and the sleeve 36
By applying hydraulic pressure in a direction opposite to the radial elastic force of the sleeve 36, the sleeve 36 is elastically deformed to clamp or unclamp the sleeve 36 with respect to the tie rod 34. The reaction force due to the hydraulic pressure during clamping and the reaction force due to the mold clamping force during mold clamping (hereinafter referred to as "reaction force such as mold clamping force") are applied to the upper and lower ends of the hollow double-acting piston 35. It is received at the joint between the bush holders 38a, 38b and the hollow double-acting piston 35 (see Japanese Patent Laid-Open No. 62-62723).

(b) As shown in FIG. 4, a sleeve 40 that is elastically deformable in the radial direction is fitted to the rod 41 of the molding machine so as to be slidable in the axial direction thereof, and the sleeve 40 is elastically deformable in the radial direction.
A female threaded part 42a formed on the inner peripheral surface of a sleeve hole 42 of a housing 43 integrally provided on a movable platen (not shown) is screwed into a male threaded part 40a provided over almost the entire length of the outer peripheral part of the A gap created between the portion 40a and the female threaded portion 42a is used as a clamp oil chamber, and a first oil chamber 44 and a second oil chamber 45 are provided at both ends of the clamp oil chamber, respectively. Then, by supplying pressurized oil from the supply hole 46 to the first oil chamber 44 and contracting the sleeve 40 in the radial direction, the inner circumferential surface of the sleeve 40 is brought into contact with the outer circumferential surface of the rod 41, resulting in a frictional force. (Refer to Japanese Unexamined Patent Publication No. 157504/1983).

[The problem that the idea aims to solve]

Among the above conventional techniques, (a) receives the reaction force such as the mold clamping force at the joint between the bush holder and the hollow double-acting piston, so that the joint strength of the joint is adjusted to the reaction force such as the mold clamping force. The bushing holder had to be set to be strong enough to withstand it, and the bushing holder had to be constructed in a large size, which resulted in the problem that the overall length of the mold clamping device became long and its weight increased. Also,
In the case of (b), since the sleeve and the housing are screwed together over almost the entire length, the threaded part must be machined with high precision, which increases the processing cost and requires the first oil There was a problem in that a certain amount of time (hereinafter referred to as "mold clamping time") was required for the pressure of the pressure oil supplied to the chamber to propagate to the second oil chamber.

The present invention was made in view of the problems of the above-mentioned conventional technology, and aims to provide a friction clamping device for a molding machine that allows the sleeve to be made smaller and does not require high-precision machining. The purpose is

[Means to solve the problem]

In order to achieve the above object, the friction clamp type mold clamping device of the present invention is slidably provided on a fixed plate and a tie rod protruding from the fixed plate via the mold clamping device, and is moved by a mold opening/closing means. The mold clamping device includes a hollow mold clamping ram having a plurality of different diameter portions whose inner diameters gradually increase from the fixed platen side in a cylinder provided integrally with the movable platen. a sleeve having a plurality of collar portions whose outer diameters are gradually enlarged from the stationary platen side in correspondence with the plurality of different diameter portions within the mold clamping ram, and which is elastically deformable in the radial direction; are fitted to form a plurality of mold clamping pressure chambers between them, and adjacent mold clamping pressure chambers are communicated with each other through small holes, and the sleeve is slidably and loosely fitted to the tie rod. .

[Effect]

When no pressurized fluid is supplied to the mold clamping pressure chamber,
A gap exists between the sleeve and the tie rod, and the sleeve is guided by the tie rod and is slidable in the axial direction. In this state, the mold opening/closing means moves the movable platen toward the fixed platen to a predetermined position before closing the mold, and then supplies pressure fluid to the fastening pressure chamber to elastically deform the sleeve in the radial direction. By bringing the inner peripheral surface into contact with the outer peripheral surface of the tie rod,
Fastened by frictional force. Next, when pressurized fluid pressure is applied to the cylinder in the mold clamping direction, the mold clamping ram is fixed to the tie rod together with the sleeve, which is clamped and fixed to the tie rod, so the movable platen moves in the fixed platen direction. The mold moves to generate a mold clamping force, and the mold is strongly clamped. The reaction force due to this mold clamping force acts in the direction of moving the mold clamping ram away from the fixed plate, but this reaction force is received by the multiple flanges of the sleeve, so the stress in the sleeve is dispersed and stress concentration is reduced. Does not occur.

When taking out the molded product, fluid pressure is applied to the mold clamping ram in the direction opposite to the fixed plate to move the movable plate in the direction opposite to the fixed plate and release the mold, and then the fluid pressure to the clamping pressure chamber is released. Then, the sleeve and tie rod are unfastened, and then the movable platen is moved in the direction opposite to the fixed platen by the mold opening/closing means to open the mold.

〔Example〕

Examples will be described based on the drawings.

As shown in FIG. 1, a tie rod 4 protruding from a fixed platen 3 is provided with a movable platen 2 so as to be slidable via a mold clamping device 1, and the movable platen 2 is connected to a mold opening/closing cylinder 5.
The mold is closed or opened by moving it toward or away from the fixed plate using a mold opening/closing means such as the above. In the figure, 2a indicates a movable mold attached to the movable platen 2, and 3a indicates a fixed die attached to the fixed platen 3.

FIG. 2 shows details of the mold clamping device 1, in which a hollow mold clamping ram 11 is disposed in a cylinder 12 integrally provided on the movable platen 2, and the inner peripheral surface of the mold clamping ram 11 is , there are three different diameter parts 11 of a small diameter, a medium diameter, and a large diameter, whose inner diameters are gradually enlarged from the fixed plate side.
a, 11b, and 11c are formed. On the other hand, the sleeve 10 is configured to be elastically deformable in the radial direction, and its outer circumferential portion has an outer diameter on the fixed platen side corresponding to the stepped portions of the different diameter portions 11a, 11b, or 11c of the mold clamping ram 11. Flange portions 10a, 10b, 10c, and 10d of different diameters are formed that gradually expand from the top. The sleeve 10 is inserted into the mold clamping ram 11, and the flange 10d on the side opposite to the fixed plate is connected to the plurality of bolts 10.
The flange portions 10a, 10 of each of the different diameter portions between the two are fixed by being fixed to the end of the mold clamping ram by g.
Three fastening pressure chambers 17a, 17b, 17c partitioned by b, 10c, 10d are formed, and the fastening pressure chambers 17a, 17b and 1 are adjacent to each other.
7c are communicated through small holes 10e and 10f formed in the flanges 10b and 10c, respectively. Furthermore, a bush 16 is fixed to the upper opening of the cylinder 12 with a plurality of bolts 16a,
A plurality of bolts 18 are inserted into the opening in the lower part of the cylinder 12 into which the tie rod 4 is inserted.
a, and the piston part 11 of the mold clamping ram 11
A mold opening pressure chamber 13 and a mold clamping pressure chamber 14 are formed on the opposite side of the fixed platen and the mold opening pressure chamber 14 are formed on the side opposite to the fixed platen, respectively, and the supply hole 13a of the mold opening pressure chamber 13 or the supply hole of the mold clamping pressure chamber 14 is formed between the mold opening pressure chamber 13 and the fixed platen side. Mold release or mold clamping is performed by supplying pressure fluid to each hole 14a.

Next, the operation of this embodiment will be explained.

When the mold is opened, the mold opening/closing cylinder 5 is operated to move the movable platen 2 toward the fixed platen 3 and to a predetermined position before closing the mold. And introduction hole 1
5, the pressurized fluid is supplied from the fastening pressure chamber 17c to the fastening pressure chamber 17b through the small hole 10f, and then to the fastening pressure chamber 1 through the small hole 10e.
7a and shrinks the sleeve 10 in the radial direction.
The inner circumferential surface of the sleeve 10 and the outer circumferential surface of the tie rod 4 are brought into strong contact with each other so that they are fastened by frictional force.

Then, when pressurized fluid is supplied to the mold clamping pressure chamber 14 from the supply hole 14a, the sleeve 10 is
Since the mold clamping ram 11 fixed to the sleeve 10 is fixed to the tie rod 4, the mold clamping pressure chamber 1
The pressure of the pressurized fluid in 4 acts to move the movable platen 2 toward the fixed platen 3, and moves the movable platen 2 toward the fixed platen, so that mold clamping can be performed with a strong mold clamping force. . At this time, a reaction force due to the mold clamping force is applied to the mold clamping ram 11, and a force acts on the mold clamping ram 11 in the direction opposite to the fixed plate. The flange part 10b, 1
Since the stress is received at 0c and 10d, the stress generated in the sleeve 10 is dispersed, and concentrated stress does not occur.

When taking out the molded product, the supply of pressurized fluid is switched from the mold clamping pressure chamber 14 to the mold opening pressure chamber 13, and by supplying pressurized fluid to the mold opening pressure chamber 13, the movable platen 2 is moved in the direction opposite to the fixed platen. After releasing the mold, the fluid pressure to each of the fastening pressure chambers 17a, 17b, and 17c is released to release the fastening between the sleeve 10 and the tie rod 4, and then the mold opening/closing cylinder 5 moves the movable platen 2 in the direction opposite to the fixed platen. Move it to open the mold.

[Effect of idea]

Since the present invention is configured as described above,
This produces the effects described below.

By setting the length of the sleeve to be relatively short, the mold clamping device can be made compact, and processing and assembly are easier than with conventional screw connections.

Furthermore, after the sleeve and tie rod are fastened at a predetermined position, the amount and pressure of pressurized fluid supplied to the mold clamping pressure chamber is controlled to control the mold clamping speed and mold clamping force pattern of the movable platen. Can be done.

[Brief explanation of the drawing]

Fig. 1 is a front view of a molding machine equipped with the mold clamping device of the present invention, and Fig. 2 is a sectional view of the main parts of the mold clamping device.
FIG. 3 is a partial sectional view of a molding machine equipped with a conventional mold clamping device, and FIG. 4 is a sectional view of the main part of a conventional friction clamping device. 1... Mold clamping device, 2... Movable plate, 2a... Movable type, 3... Fixed plate, 3a... Fixed type, 4... Tie rod, 5... Mold opening/closing cylinder, 10... Sleeve, 10a, 10b, 10c, 10d...Tsubabe,
10e, 10f...Small hole, 11...Mold clamping ram, 1
1a...Small diameter part, 11b...Medium diameter part, 11c...
Large diameter part, 11d...Piston part, 12...Cylinder, 13...Mold opening/closing pressure chamber, 14...Mold clamping pressure chamber, 15...Introduction hole, 16, 18...Button,
17a, 17b, 17c... fastening pressure chambers.

Claims (1)

[Scope of Claim for Utility Model Registration] A fixed platen 3 and a movable platen 2 slidably provided on a tie rod 4 protruding from the fixed platen 3 via a mold clamping device 1 and moved by a mold opening/closing means 5. The mold clamping device 1 includes a plurality of different diameter portions 11a, 11b, 11 whose inner diameters are gradually enlarged from the fixed platen side in a cylinder 12 that is integrally provided on the movable platen 2.
A hollow mold clamping ram 11 having a shape of c is disposed, and inside the mold clamping ram 11, the outer diameters of the different diameter portions 11a, 11 are arranged.
A plurality of flanges 10a, 10b, 10c, 1 expanded in stages from the fixed plate side corresponding to b, 11c.
A plurality of fastening pressure chambers 17a, 17 are formed by fitting a sleeve 10 having a diameter of 0d and being elastically deformable in the radial direction.
b, 17c, and the adjacent fastening pressure chambers are communicated with each other through small holes 10e, 10f,
Furthermore, the friction clamp device for a molding machine is characterized in that the sleeve 10 is slidably and loosely fitted into the tie rod 4.