JPS6236818B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic clamp device for fixing a tool, etc. (referring to a tool or a workpiece) to a machine tool (referring to a metal processing machine or a cutting machine), which can be made compact and has a clamping force that is low. The purpose is to easily and accurately set the value to a predetermined value, and to prevent tools, etc. from coming off after clamping.

Conventionally, there is a type in which the clamp arm is pressed toward the clamp side using a hydraulic cylinder. However, in this case, when the pressure of the hydraulic cylinder leaks, the clamp falls off, causing the tool etc. to shift or fall, resulting in damage.

In order to eliminate this, it is possible to press the clamp arm toward the clamp side with a spring. In this case, in order to produce a clamping force of 4 tons, for example, even if a lever booster mechanism (2x boost factor) is combined, a very large spring must be used that can produce a force of 2 tons. First, the overall size of the hydraulic clamp device becomes larger, which significantly increases its manufacturing cost.In addition, as the installation space becomes larger, the maximum dimensions of tools, etc. that can be fixed to a fixed size mounting base become smaller. limited.

In order to further eliminate these drawbacks, it is conceivable to press the clamp arm toward the clamp side using the tightening force of the screw. However, it is impossible to produce a tightening force of, for example, 2 tons by hand, and it is impossible to implement this method. Even if it were possible to do so, it would be hard work, and there would be a large error in the tightening force, as it would be impossible to know whether the tightening force had been tightened to the specified 2 tons.

In order to eliminate the above-mentioned drawbacks, the present invention utilizes the fact that the clamp arm is elastically deformed during clamping, and
After pressing the clamp arm toward the clamp side with a hydraulic cylinder, the clamp arm is held in an elastically deformed clamped state by a mechanical locking device, and the clamping force is mechanically held in place by the locking device, and at the same time, vibration and impact This is to prevent this clamping condition from loosening even if the

Embodiments of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 indicates a clamp body, and its T-shaped leg 2 is a machine tool (for example, a press machine, a lathe, a
It is fixed to a T-slot 5 of a mounting base 4 for tools 3 of a milling machine so that it can move forward and backward. Reference numeral 6 denotes a clamp arm, which has a fulcrum hole 7 in its middle portion, a force point surface 8 on its lower right end surface, and an action point surface 9 on its left lower surface. The fulcrum hole 7 is swingably supported by a fulcrum pin 11 to a pair of front and rear pivot brackets 10 erected on the left half of the clamp body 1, and the force point surface 8 is connected to the ram 1 of a single-acting hydraulic cylinder 12.
3, it is pushed up toward the upper right side of the clamp, and the application point surface 9 is pushed down and pressed into contact with the tool 3. In order to pull back the clamp arm 6 downward to the right when unclamping the clamp, an unclamp spring 15 is attached to the spring assembly chamber 14 which is vertically recessed in the center of the clamp body 1, and this spring 15 is used to pull the rod 16. The rod 16 is pivoted to the clamp arm 6 with a pin 17 pivotally attached to the clamp arm 6 so as to be able to swing freely.

The hydraulic cylinder assembly chamber 18 is recessed in the right half of the upper surface of the clamp body 1, and the hydraulic cylinder 12 is installed here.
A hydraulic hose 21 is connected to an oil passage hole 20 communicating with the hydraulic chamber 19, and this is connected to a hydraulic system (not shown).

In the lock device 22, a locking tool 23 is swingably mounted on the side surface above the force point of the clamp arm 6 using a pivot pin 24, and in a clamped state, the locking tool 23 is swinged downward to lock the tip of the locking tool 23. The abutment surface 25 is formed to abut against a receiving surface 26 on the upper end surface of the hydraulic cylinder 12 to achieve a clamping posture in which the force point side of the clamp arm 6 is restrained and supported. The cam surface is formed such that as the rocking progresses, the part that comes into contact with the receiving surface 26 becomes farther away when viewed from the pivot pin 24. The switching spring 27 is formed by fixing one end to the clamp arm 6 and the other end to the locking tool 23, and the tension of the switching spring 27 moves the locking tool 23 into the unlocked position (FIG. 1) or into the clamp lock. It is formed so that it can be held stably in either posture (Fig. 3).

A stopper 28 is attached to the clamp arm 6 to prevent the locking tool 23 from swinging upward excessively in the unlocked position, and a stopper 28 is attached to the clamp arm 6 to prevent interference between the stopper 28 and the locking tool 23 when swinging to the clamp locking position. A recess 29 is formed on the back surface of the locking tool 23, and a handle 30 for gripping is provided on the front surface of the locking tool 23.

Next, its effect will be explained.

The clamp arm 6 is pressed from the unclamped state upward to the left by the unclamping spring 15 to the clamped state upward to the right by actuating the hydraulic cylinder 12, and presses and fixes the tool etc. 3 to the mounting base 4. . At this time, if the initial clamping force with which the application point surface 9 presses and fixes the tool 3 is 4.5t, and the lever ratio of the clamp arm 6 is 2:1, the application point surface 8 is applied to the cylinder 1.
2 is pushed up by 2.25t, and the sum of 4.5t and 2.25t
The fulcrum hole 7 is pushed down by a reaction force of 6.75t. Therefore, the clamp arm 6 is elastically deformed into an arched shape, and the force point surface 8 is pushed up with the force point surface 9 as a fixed end.

In this state, when the locking tool 23 is swung downward to bring its abutment surface 25 into contact with the receiving surface 26 to take the clamp lock position, the amount of elastic deformation of the clamp arm 6 returns slightly (about 10%). Therefore, although the clamping force also decreases to the same extent, substantially the initial clamping force can be maintained.

In addition, the locking tool 2 may be damaged due to shock or vibration from the tool 3.
At the moment when the abutment surface 25 and the receiving surface 26 of No. 3 come out of contact, the locking tool 23 further swings downward under the tension of the switching spring 27 (as shown by the chain line in FIG. 3), and the abutment surface 25 mentioned above Because of the cam surface, the locking tool 23 bites into the contact surface 25 and the receiving surface 26 to maintain the clamped state and maintain the clamping force.

It should be noted that, as a modification of the embodiment of the invention described above, the locking device 22 can also be mounted on both sides of the clamp arm 6.

Since the present invention is constructed and operated as described above, it produces the following effects.

(a) Since the clamp arm is mechanically held in place by a swinging locking device, the clamp will not fall off even if pressure from the hydraulic cylinder leaks. Thereby, accidents such as damage to tools etc. due to falling off of the clamp can be eliminated.

(b) The clamping force at the start of clamping is generated by a hydraulic cylinder, and by increasing the hydraulic pressure of the hydraulic cylinder, it can be made compact and high output. Moreover, the locking tool can be made small and high in strength. Therefore, the entire hydraulic clamping device can be made sufficiently small and manufactured at low cost, and the maximum dimensions of tools that can be fixed to the tool mounting base can be reduced by the small installation space required for the hydraulic clamping device. You can make it bigger.

(c) The clamp arm can be tightened easily and quickly with a large force using a hydraulic cylinder, and the clamping force can be maintained at a specified value by visually checking the hydraulic pressure with a pressure gauge or by adjusting the pressure to a specified pressure using a constant pressure valve. Can be matched accurately. Further, this clamping force can be properly maintained with a locking tool. Therefore, tools, etc. can be easily, quickly and accurately tightened and fixed with a predetermined force, and tools, etc. can be properly fixed for a long time.

(d) The clamping force can be held by a locking device and not by a hydraulic cylinder. In this case, for example, when working with a mold fixed to the ram of a press, the clamping force can be used to hold the clamping force from the hydraulic clamping device. By removing the hydraulic hose, it is possible to eliminate fatigue damage and damage caused by the hydraulic hose being repeatedly raised and lowered.

(E) The clamp lock will not loosen even if large vibrations or shocks transmitted to the clamp arm from tools etc. continue for a long time.
Rather, since the locking tool digs in, the clamped state can be maintained reliably.

(F) The locking tool is attached to the clamp arm, and tension is applied to it by a switching spring, so that it is held stably in both the clamp locking position and the unlocking position. Switching to and from the release position can be performed accurately and easily with a single touch.

(g) It has a simple structure, can be implemented at low cost, and can be easily implemented into existing clamping devices.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is a longitudinal sectional side view of a main part, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a partial side view in a clamped state. DESCRIPTION OF SYMBOLS 1... Clamp body, 6... Clamp arm, 7... Fulcrum part, 8... Force point part, 9... Point of action part, 12... Hydraulic cylinder, 23... Locking tool, 24... Pivotal pin, 25...
A surface that comes into contact with the receiving surface 26 of the locking tool 23, 26... receiving surface, 27... switching spring.

Claims (1)

[Claims] 1 A fulcrum part 7, a force point part 8, and an action point part 9 are formed on the clamp arm 6, the fulcrum part 7 is pivotally supported on the clamp body 1, and the force point part 8 can be pushed toward the clamp side by the force of the hydraulic cylinder 12. The hydraulic cylinder 1
Reference numeral 2 denotes a locking member 23 that is attached to the clamp body 1 and holds the force point part 8 in the clamp position pressed by the force of the hydraulic cylinder 12, and a pivot pin 24 on the side of the force point part 8.
The locking tool 2
By fixing the receiving part 26 of No. 3 upward to the clamp body 1, the locking tool 23 is pivoted downward and comes into contact with the receiving surface 26, and the locking tool 23 is pivoted upward and separated from the receiving surface 26. The locking tool 23 is configured to be able to swing freely between the unlocking position and the switching spring 2.
7, it is configured so that it can be held in either the clamp lock position or the lock release position, and the lock tool 2
A machine tool configured by forming a surface 25 that contacts the receiving surface 26 of No. 3 into a cam surface that becomes farther away from the pivot pin 24 as the downward swing progresses. Hydraulic clamping device.