JPH0753875Y2 - Clamp confirmation detection device in fluid pressure clamp device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a detection device for confirming completion of tightening work in a fluid pressure device such as a hydraulic clamp for performing tightening work.

(Prior Art) Conventionally, for example, in a device such as a hydraulic vise used for holding and fixing an unspecified object, in order to confirm whether or not the object is securely tightened and fixed at a predetermined position, a hydraulic pressure is used. There was a pressure switch in the circuit. The reason is that when the hydraulic vise completes the tightening work, the operation of the hydraulic vise stops and the hydraulic pressure in the circuit rises to a preset pressure, so the pressure switch measures and the set pressure is detected. This is because it can be confirmed from time to time that the tightening work has been completed. Therefore, a confirmation signal is issued from the pressure switch and the hydraulic circuit leading to the hydraulic vise is closed. However, when the object to be tightened is a thin-walled pipe, for example, it is necessary to appropriately lower the pressure of the hydraulic oil sent to the hydraulic vise in order to prevent the deformation of the pipe. Therefore, it is necessary to adjust and reduce the set pressure when the pressure switch confirms the completion of the tightening work.

(Problems to be Solved by the Invention) Changing the set pressure of the pressure switch described above requires a considerable amount of labor when, for example, it becomes necessary to clamp an unspecified number of objects one after another. In addition, there was a risk of causing various accidents due to an error in the pressure setting work.

[Structure of the Invention] (Means for Solving the Problem) In order to solve the above-mentioned conventional problems, in the present invention, in order to operate the fluid pressure clamp device, the direction of opposition to the flow of the fluid flowing through the circuit is applied. Provided is a clamp confirmation and detection device, in which a detected part is provided on a valve body that is biased by a spring or the like and is restricted to reciprocate, while a detector for detecting movement of the detected part is provided on the valve body. It is a thing.

(Operation) In the above configuration, when a hydraulic vice is used, for example, to appropriately tighten the object, the hydraulic oil whose pressure is adjusted is first introduced to the inlet of the clamp confirmation detection device, and the clamp confirmation detection device is introduced. After passing through the interior of the hydraulic vice, the hydraulic vice is actuated to flow into the pressurizing cylinder of the hydraulic vice, and the work of tightening the object is performed. When the tightening work is completed, the movement of the piston in the pressurizing cylinder is stopped, and as a result, the inflow of hydraulic oil is stopped.

In the above operation, the clamp confirmation detection device outputs a signal that the hydraulic oil is flowing in as the first step, and the inflow of the hydraulic oil is stopped as the second step, and the flow of the hydraulic oil inside the clamp confirmation detection device is stopped. It outputs a signal that it has stopped. Therefore, since the tightening work is confirmed to be completed by the signal of the second stage, the hydraulic circuit for the above operation can be controlled.

Embodiment An embodiment according to the present invention will be described above with reference to the drawings.

FIG. 2 shows a hydraulic vise 3 having a well-known structure which is used as a fluid pressure clamp device 1 for clamping and fixing the material W, for example, when cutting the material W such as a pipe in a band saw machine and the like. 3 is a diagram showing a hydraulic circuit 5 of FIG. The hydraulic vise 3 has a fixed vise jaw 7 and a movable vise jaw 9. By applying hydraulic pressure to the cylinder 11 of the movable vise jaw 9, the movable vise jaw 9 cooperates with the fixed vise jaw 7 to clamp and fix the material W. To do.
In FIG. 2, the hydraulic oil pressurized by the hydraulic pump P is passed through the solenoid valve 13 and further adjusted to a predetermined hydraulic pressure by the pressure regulator 15, and then passes through the clamp confirmation detecting device 17, which will be described in detail later. Then, the cylinder 11
And the movable vice jaw 9 is moved to fix the material W. When the work of fixing the material W is completed, it is desirable to operate the solenoid valve 13 to bring the movable vice jaw 9 to the neutral position. Therefore, a confirmation signal is required when the movable vice jaw 9 completes the material fixing work. Next, a clamp confirmation detection device that outputs this confirmation signal will be described in detail with reference to FIGS. 1 (a) and 1 (b).

The clamp confirmation detection device 17 is provided with a valve seat 23 having an inflow port 23 for inflowing hydraulic oil to one end (lower part in FIGS. 1A and 1B) of a hollow cylindrical body 19. One end facing the valve seat 23 (Fig. 1 (a), (b))
A discharge port 25 for discharging hydraulic oil is provided in the upper part of FIG. A detector 27 utilizing a magnetic proximity switch known as a reed switch is provided on the inner wall of the body 19, and is connected to a control device (not shown) via a lead wire 29. Inside the body 19, a hollow cylindrical valve body 31
Is inserted and slidable on the inner wall surface of the body 19 so as to be reciprocally movable on a straight line. One end of valve body 31 (first
There is a cylindrical protrusion 33 in the lower part of FIG.
Small holes 35 and 37 are formed on the side surface of the protruding portion 33, and communicate with an empty space 39 inside the valve body 31. Further, the protrusion 33 of the valve body 31
A ring-shaped magnet is fitted on the side surface close to
Are configured. The internal space 39 of the valve body 31 is stepped, a coil spring 45 is inserted into contact with the stepped surface 43, and the other end of the coil spring 45 has a body 19
It is in contact with the outer edge of the discharge port 25, presses the valve body 31, and urges the protrusion 33 with a weak force so as to close the inflow port 21. There are ring-shaped grooves at both ends of the outer surface of the valve body 31, and oil seals 47 and 49 are attached.

In the above configuration, the inflow port 21 is connected to the pressure regulator 15 and the circuit 5 communicating with the hydraulic pump P, and the discharge port 25 is connected to the hydraulic circuit 5.
Through the cylinder 11 of the movable vice jaw 9.

When hydraulic oil adjusted to a predetermined pressure flows from the inflow port 21 of the clamp confirmation and detection device 17, the protrusion 33 retreats against the biasing force of the coil spring 45, as shown in FIG. 1 (b). The hydraulic oil passes through the small holes 35 and 37, reaches the cylinder 11 from the discharge port 25 through the circuit 5 through the space 39 inside the valve body, moves the movable vice jaw 9, and moves the material W. Fix it. As a result, when the flow of hydraulic oil stops, the flow of hydraulic oil also stops inside the body 19 of the clamp confirmation detection device 17. Therefore, the valve body 31 is released from the pressure in the downstream direction, which opposes the biasing force of the coil spring 45, and the valve body 31 returns to the position shown in FIG.

Along with the reciprocating motion of the valve body 31 as described above, the detected portion 41 composed of a ring-shaped magnet also moves from the state shown in FIG. 1 (a) to the position shown in FIG. The state of FIG. 1 (a) is restored. At this time, the reed switch of the detector 27 is not affected by the magnetic force of the detected portion 41 composed of a magnet in the state of FIG. 1 (a), so that the contact portion 51 inside the reed switch is not affected. Although it is in the open state, when the magnet of the detected part 41 approaches as shown in FIG. 1 (b), the contact part 51 is closed due to the influence of the magnetic force, and a current is passed through the lead wire 29 to cause the above-mentioned first step. Signal of. Then, when the state of FIG. 1 (a) is restored again, the contact portion 51 is opened again, and the current is cut off. The solenoid valve 13 can be operated to close the hydraulic circuit to the movable vice jaw 9 by using the interruption of the electric current as the signal of the second stage.

Even when the pressure of the hydraulic oil is adjusted to be low because the biasing force of the coil spring 45 is weak due to the above-described action of the clamp confirmation detection device 17, the valve body 31 moves as described above and the detector 27 also operates as described above. The signals of the first stage and the second stage will be transmitted. Therefore, even when the pressure of the hydraulic oil is changed in accordance with the strength of the material W, the above-described operation of the clamp confirmation and detection device 17 is not affected and no special adjustment is required.

When releasing the tightened material W, the hydraulic oil does not pass through the clamp confirmation detection device 17, but passes through a bypass circuit 53 provided in parallel with the clamp confirmation detection device 17 and the hydraulic oil tank 55. Returned to.

In the above embodiment, a reed switch is used as the detector 27 and a magnet is used as the detected portion 41, but various other sensors such as photocouplers and condenser type sensors that utilize reflection of light rays are used. Contact-type control devices such as contact sensors or limit switches can also be used.

Besides, the present invention is not limited to the description of the above-mentioned embodiment, but can be implemented in various modes by making appropriate changes.

[Effects of the Invention] As can be understood from the above description of the embodiments, according to the present invention, it is possible to easily confirm the completion of the clamping work when using the hydraulic clamping device that requires adjustment of hydraulic pressure.
Moreover, even if the hydraulic pressure used is changed, it is not necessary to adjust the clamp confirmation detection device, so that the efficiency of the clamp work can be improved.

[Brief description of drawings]

1 (a) and 1 (b) are sectional views showing an embodiment of the present invention. FIG. 2 is a circuit diagram showing one embodiment of a hydraulic circuit for carrying out the present invention. 1 ... Fluid pressure clamp device, 5 ... Circuit, 17 ... Clamp confirmation detection device, 27 ... Detector, 31 ... Valve body, 41 ... Detected part

Claims (1)

[Scope of utility model registration request] 1. A sensed portion 41 is provided on a valve body 31 which is biased in a direction against a flow of a fluid flowing through a circuit 5 for operating a fluid pressure clamp device 1 and is regulated to reciprocate. A clamp confirmation and detection device comprising a detector 27 for detecting the movement of the detected portion 41 of the valve body 31.