JPH0512890U - Quick fitting with check valve - Google Patents

Abstract

(57) [Summary] [Purpose] To facilitate pressure relief of the hydraulic circuit on the plug side in a quick joint with a check valve. [Structure] A check valve seat 37 and a check valve chamber 38 are sequentially provided in a casing 31 of a plug 8b of a quick coupling from the tip side. The non-return valve body 39 inserted in the non-return valve chamber 38 is closed by the non-return spring 41 to the non-return valve seat 37 so as to close the valve. A protective cap 51 is screwed onto the outer peripheral surface of the casing 31 so as to move back and forth in the joint connecting direction. The cap 51
The bottom wall 51a is provided with a forced valve opening pressing portion 55 that comes into contact with the tip portion 39a of the check valve body 39. A liquid storage chamber 56 is provided on the peripheral wall 51b of the cap 51.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a quick joint with a check valve.

[0002]

[Prior Art]

 In general, a quick joint with a check valve moves the first joint toward the second joint by the connection operation force by human power, and the check valve body built in the second joint is forced against the check spring. It is designed to open the valve. However, when pressure remains in the circuit on the second joint side, it becomes difficult to open the check valve body against the pressure.

In order to solve this problem, the present inventor has previously proposed the technique disclosed in Japanese Utility Model Publication No. 63-34824. This is because a pressure relief on-off valve is provided in the hydraulic circuit on the second joint side, and the above-mentioned on-off valve is opened to connect the hydraulic circuit on the second joint side to atmospheric pressure before connecting and operating the quick coupling. It is configured to decrease.

[0004]

[Problems to be solved by the device]

 When the above-mentioned on-off valve is opened, the pressure oil on the second joint side is vigorously discharged from the on-off valve, so that the equipment chamber is contaminated with oil. To solve this problem, it is conceivable to connect the outlet of the on-off valve and the oil tank with a return pipe. However, in this case, the space for the return pipe is required and the production cost is increased, which is a new problem. The present invention aims to achieve both prevention of oil pollution and reduction of manufacturing cost.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention is configured as follows, for example, as shown in FIG. A non-return valve seat 37 and a non-return valve chamber 38 are sequentially provided in the casing 31 of the plug 8b which is the second joint from the front end side in the joint connecting direction, and the non-return valve body 39 inserted in the non-return valve chamber 38 is provided. The check valve seat 37 is provided with a check spring 41 for elastically closing the valve, and a protective cap 51 is screw-fitted onto the outer peripheral surface of the casing 31 so as to be movable back and forth in the joint connecting direction, and the inner surface of the cap 51 is The forced valve opening pressing portion 55, which contacts the tip portion 39a of the check valve body 39, is provided, and the liquid storage chamber 56 is provided.

[0006]

[Action]

 The present invention operates as follows, for example, as shown in FIG. After the socket 8a is separated from the plug 8b, a protective cap 51 is fitted on the casing 31 of the plug 8b as shown in FIG. This prevents foreign matter such as dust from adhering to the outer peripheral surface of the casing 31 for connection.

When reconnecting the rapid coupling 8, the cap 51 is operated as shown in FIGS. (B) to (c) prior to the connecting operation. That is, the cap 51 is screwed into the casing 31, and the cap 51 is strongly advanced to the right by the screw thrust. Then, the forced valve opening pressing portion 55 of the cap 51 comes into contact with the tip end portion 39a of the check valve body 39 to resist the elastic force of the check spring 41 and the oil pressure in the check valve chamber 38. Then, the check valve body 39 is separated from the check valve seat 37. As a result, the high-pressure liquid in the check valve chamber 38 is discharged from the casing 31 to the liquid storage chamber 56 of the cap 51, and the plug side circuit is depressurized. Then, as shown in FIG. 3A, the cap 51 is removed from the casing 31 and the oil in the cap 51 is returned to the oil tank or the like.

[0008]

[Effect of the device]

 The present invention has the following effects because it is configured and operates as described above. During depressurizing operation of the plug side circuit, the liquid in the circuit is contained in the protective cap and is not discharged to the outside, so the equipment room is not contaminated with liquid. Further, in order to obtain the above effects, unlike the conventional example, it is not necessary to provide a liquid return pipe, so that the piping space can be omitted and the entire device can be manufactured at low cost. Further, since the protective cap can also serve as the pressure releasing means, the pressure releasing on-off valve of the conventional example can be omitted, and the manufacturing cost of the entire apparatus can be further reduced.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS.

The circuit diagram of FIG. 2 shows a hydraulic clamp device to which the present invention is applied. This apparatus presses and fixes a work piece 3 on a fixed frame 2 of a work pallet 1 carried into a machining center by a clamp tool 5 of a hydraulic clamp 4. The hydraulic clamp 4 is composed of a single-action spring return type hydraulic cylinder. The hydraulic working chamber 4a is connected to the switching valve 9 through the working port A and the pressure port P of the check valve 6 with the valve opening function, the supply / discharge passage 7, and the quick joint 8 with the double-sided check valve. The switching valve 9 is arranged outside the work pallet 1.

When clamping the workpiece 3, the first joint 8a of the quick joint 8 is connected to the second joint 8b, the check valve 6 is switched to the supply position X by the forced valve opening means 6a, and the switching valve is 9 is switched to the supply position M. Then, the pressure oil from the hydraulic power source 11 is supplied to the working chamber 4a through the switching valve 9, the quick coupling 8, and the check valve 6 in this order, and the clamp 5 presses and fixes the work piece 3.

In this clamped state, the quick joint 8 is separated, the work pallet 1 is carried into the machining center, and then the work piece 3 is processed. At this time, the hydraulic working chamber 4a is doubly sealed by the check valve 6 and the check valve in the second joint 8b, so that the pressure leakage is surely prevented. After the work piece 3 is processed, the work pallet 1 is unloaded from the machining center, and then the clamped state of the worked work piece 3 is released.

During unclamping of the machined workpiece 3, the quick joint 8 is connected to switch the check valve 6 to the discharge position Y and the switch valve 9 to the discharge position N. Then, the pressure oil in the working chamber 4a is returned to the oil tank 12 through the path of the check valve 6, the quick coupling 8 and the switching valve 9 by the elastic force of the return spring 4b. As a result, the worked work piece 3 is released from the clamped state and can be taken out of the work pallet 1.

When a new workpiece 3 is clamped, the check valve 6 is switched to the supply position X and the switching valve 9 is switched to the supply position M as described above to supply pressure oil to the hydraulic clamp 4. Of.

As shown in FIG. 3, the rapid joint 8 is configured so that the first joint 8a made of a socket is connected to the second joint 8b made of a plug. The first joint 8a is a commercially available product that is used as it is, and the receiving hole 22, the check valve seat 23, and the check valve chamber 24 are formed in the casing 21 in order from the front end side in the joint connecting direction. Then, the check valve body 25 inserted in the check valve chamber 24 is closed by the check spring 26 to close the check valve seat 23.

The second joint 8b described above includes two check valves. That is, the main check valve seat 33 and the main check valve chamber 34 are sequentially formed in the insertion cylinder 32 of the casing 31 from the tip end side in the joint connection direction, and the main check valve chamber 34 is inserted into the main check valve chamber 34. A sub check valve seat 37 and a sub check valve chamber 38 are sequentially formed in the valve body 35 from the front end side. The sub check valve body 39 inserted in the sub check valve chamber 38 is closed by the check spring 41 to the sub check valve seat 37, and the main check valve body 35 is closed by the check spring 41. A valve closing pressure is applied to the main check valve seat 33. Reference numeral 43 is a spring receiver.

The above-described double speed couplings 8a and 8b are connected and operated as follows. First, the first joint 8a is advanced rightward toward the second joint 8b in a state where the sleeve 27 of the first joint 8a is retracted leftward to free the plurality of lock balls 28. Then, first, the receiving hole 22 is externally fitted to the insertion tube 32, and the O-ring 29 is brought into sealing contact with the outer peripheral surface of the insertion tube 32. At the same time, the front end portion 25a of the check valve body 25 of the first joint 8a resists the elastic pressure of the check spring 41 and the oil pressure in the sub check valve chamber 38 to move the sub check valve body 39 to the sub position. The supply / discharge passage 7 is depressurized by separating it from the check valve seat 37. The non-return valve body 25 subsequently advancing separates the main non-return valve body 35 from the main non-return valve seat 33. Then, when the lock ball 28 is engaged with the lock hole 47, the connecting operation of both joints 8a and 8b is completed.

As described above, first, the small-diameter sub check valve body 39 is opened to depressurize the supply / discharge passage 7, and then the large-diameter main check valve body 35 is opened. The operating force required to connect the joint 8 is small.

Further, as shown in FIG. 1, a protective cap 51 is screwed onto the outer peripheral surface of the insertion tube 32 of the second joint 8b so as to be movable back and forth in the joint connecting direction. A female threaded portion 52 that fits into the male threaded portion 45 of the insertion tube 32 and a posture maintaining O-ring 53 that engages with the lock hole 47 are sequentially provided at the tip of the cap 51. The bottom wall 51a of the cap 51 is provided with a forced valve opening pressing portion 55 that comes into contact with the tip 39a of the sub check valve body 39, and the liquid storage chamber 56 is provided on the peripheral wall 51b of the cap 51. .. The cap 51 is connected to the right end portion of the casing 31 of the second joint 8b or the work pallet 1 by a chain 58.

The protection cap 51 is used as follows. After separating the first joint 8a from the second joint 8b, as shown in FIG. 1 (b), the protective cap 51 is fitted onto the insertion cylinder 32 of the first joint 8b to lock the insertion cylinder 32. The posture maintaining O-ring 53 is fitted in the hole 47. This prevents foreign matter such as dust from adhering to the outer surface of the insertion tube 32.

When reconnecting the quick joint 8, the cap 51 is removed from the first joint 8b and the first joint 8a is attached to the second joint 8b as described above, as shown in FIG. 1 (a). To connect. At the time of this reconnection, when the pressure in the supply / discharge passage 7 is increased due to the leakage of the check valve 6 with the valve opening function and the sub check valve body 39 cannot be opened, the cap 51 is opened. After the state shown in FIG. 1 (b), the operation is performed as shown in FIG. 1 (c).

That is, the female screw portion 52 at the tip of the cap 51 is fitted to the male screw portion 45 of the casing 31, and the cap 51 is strongly advanced to the right by the screw thrust. Then, the forced valve opening pressing portion 55 of the cap 51 contacts the tip portion 39a of the sub check valve body 39, and resists the elastic force of the check spring 41 and the oil pressure in the sub check valve chamber 38. Then, the sub check valve body 39 is separated from the sub check valve seat 37. As a result, the pressure oil in the sub check valve chamber 38 and the main check valve chamber 34 is discharged from the cylindrical hole 35a of the main check valve body 35 to the liquid storage chamber 56 of the cap 51.

Next, as shown in FIG. 1 (a), the cap 51 is removed from the second joint 8 b, and the oil in the cap 51 is returned to the oil tank 12. Subsequently, as shown in FIG. 3, the first joint 8a is connected to the second joint 8b.

The second joint 8b made of a plug may have a sub check valve omitted. In this case, before performing the connecting operation of both joints 8a and 8b, the check valve body 35 of the second joint 8b should be opened by the cap 51, and the supply / discharge passage 7 should be depressurized in advance. Is preferred. Further, in the cap 51, the forced valve opening pressing portion 55 may be provided on the peripheral wall 51b and the liquid storage chamber 56 may be provided on the bottom wall 51a. Further, the quick joint 8 may be connected and operated by a pneumatic cylinder instead of being manually connected and operated.

[Brief description of drawings]

FIG. 1 is an operation explanatory diagram when a protective cap is connected to a plug of a quick coupling.

FIG. 2 is a circuit diagram of a hydraulic clamp device using the above quick coupling.

FIG. 3 is a view showing a plug and a socket of the above quick coupling.

[Explanation of symbols]

8 ... Rapid joint, 8b ... Plug (second joint), 31 ... Casing, 37 ... Check valve seat (sub check valve seat), 38 ... Check valve chamber
(Sub check valve chamber), 39 ... Check valve body (sub check valve body), 39
a ... Tip, 41 ... Non-return spring, 51 ... Protective cap, 5
5 ... Pressing portion for forced valve opening, 56 ... Liquid storage chamber.

Claims (1)

[Scope of utility model registration request] A check valve seat (37) and a check valve chamber (38) are provided in a casing (31) of a plug (8b) of a quick coupling (8).
A check spring (41) is provided, which is provided in order from the front end side in the joint connection direction, and the check valve body (39) inserted into the check valve chamber (38) is closed to the check valve seat (37) to elastically close the valve. In the provided quick joint with a check valve, the protective cap (51) is screwed onto the outer peripheral surface of the casing (31) so as to be movable back and forth in the joint connecting direction, and the inner surface of the cap (51) is fitted with the protective cap (51). Check valve body (39) tip
A quick joint with a check valve, characterized in that a forced valve opening pressing portion (55) abutting against (39a) is provided and a liquid storage chamber (56) is provided.