JP2006170410A - Shock prevention mechanism and pilot check valve with operation detection function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive pilot check valve with an operation detection function capable of maintaining performance of a check valve element, achieving high positional precision, preventing reduction of position detection performance, and allowing simple handling. <P>SOLUTION: The check valve element 20a is slidably provided in a valve main body 11. The check valve element 20a displaced by operation of pressure fluid communicates and shuts off fluid passages 12 and 14, 13 and 15. A needle valve element rod 37a provided in the inside of the check valve element 20a is supported on a case 31a attached to the valve main body 11. A projecting part 46a for detection is provided on the needle valve element 37a, and a contact 40a is slidably fitted into a small diameter part 39a in which the projecting part 46a for detection is formed. A ring 44a is screw-fitted into an electrically conductive rod 61a connected with a connector 55a. The contact 40a is engaged with a side wall face of the ring 44a by a spring 41a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pilot check valve, and more particularly to a shock prevention mechanism and a pilot check valve with an operation detection function that can directly detect that the position of a check valve body is operating.

  FIG. 10 is a longitudinal sectional view showing a schematic structure of a conventional modular pilot check valve 10 with a shock prevention mechanism. In FIG. 10, a modular pilot check valve 10 with a shock prevention mechanism communicates with a plurality of fluid passages formed in the valve body 11, for example, fluid passages 14 and 15 on the solenoid valve side, and fluid passages 12 and 13 on the actuator side. A piston 17 is slidably provided in the axial hole 16, and cylindrical valve seats 18 a and 18 b fitted into the valve body 11 are disposed in the vicinity of both ends of the spool 17. Furthermore, cylindrical check valve bodies 20a and 20b are slidably fitted into the valve body 11 in axial holes 19a and 19b provided coaxially with the axial hole 16. The check valve bodies 20a and 20b have a function of communicating or blocking the fluid passages 12 and 14 and the fluid passages 13 and 15 respectively by contacting or separating one end of the check valve bodies 20a and 20b from the valve seats 18a and 18b.

In this case, needle valves 21a and 21b are slidably fitted in the check holes 20a and 20b in the axial holes 23a and 23b, and the check valves 20a and 20b and the check valves 20a and 20b and The needle valves 21a and 21b move together, and the inclined surfaces formed on the check valve bodies 20a and 20b are pressed against the inner diameter end surfaces of the valve seats 18a and 18b. The needle valves 21 a and 21 b are formed so that the tip portions protrude from the check valve bodies 20 a and 20 b and engage with both end surfaces of the piston 17.
The springs 21a and 21b are engaged with the inner end faces of the openings of the lids 24a and 24b attached to the valve body 11 by screw members (not shown), and the other ends are the inner end faces of the openings of the needle valves 21a and 21b. Is attached to.
In FIG. 10, for example, when pressure fluid flows from the fluid passage 14, the pressure fluid acts on a cross-sectional area of a seat surface (not shown) in which the valve seat 18a and the check valve body 20a are engaged. . When the pressure of the pressure fluid acting on the seat surface becomes higher than the cracking pressure determined by the spring force of the spring 22a and the seat diameter of the seat surface, the check valve body 20a is pushed open, and the check valve body 20a Displacement in the direction of arrow X causes the pressure fluid to flow through the fluid passage 12. At this time, the needle valve 21a is displaced integrally with the check valve body 20a.

  On the other hand, when pressure fluid enters from the fluid passage 12, the check valve body 20a is pressed against the valve seat 18a by the elastic force of the spring 21a biased to the check valve body 20a. The valve body 20a does not open. However, in this case, the pressure fluid supplied from the pressure supply source flows in the order of the fluid passage 13, the actuator (not shown), and the fluid passages 12 and 14 in this order from the fluid passage 15. Higher than the pressure. As a result, the piston 17 moves in the direction of the arrow X, opens the needle valve 21a, releases the pressure of the fluid passage 12, and then forcibly opens the check valve body 20a. Therefore, the back flow from the fluid passage 12 to the fluid passage 14 is possible. In this case, the same operation is performed with respect to the fluid passages 13 and 15, and the check valve body 20b is displaced in the arrow Y direction.

On the other hand, in an industrial machine using a pressure fluid as a drive source, it is necessary to confirm whether the hydraulic valve directly related to the operation of the actuator is in a stopped or activated state for the safe operation of the apparatus. Therefore, a means for detecting the movement of the component parts constituting the hydraulic valve is required.
However, in the pilot check valve 10 with a shock prevention mechanism shown in FIG. 10, the movement of the constituent parts cannot be confirmed at all. Therefore, it is impossible to detect the stop or operation of the pilot check valve 10 with the shock prevention mechanism. is there.
Therefore, in Patent Document 1, the position of the spool is detected from the outside of the sealed pressure resistant space using a differential transformer. In Patent Document 2, the position of the spool in the sealed pressure resistant space is detected using a magnetic sensor.
JP-A-10-177918 JP 2002-89742 A

However, the differential transformer type as shown in Patent Document 1 has a complicated valve structure. Since a differential transformer and a dedicated electric circuit (amplifier) are required, it becomes expensive. Moreover, before use, it is necessary to adjust the position of the core which is a differential transformer or a detection body. Furthermore, there has been a problem that the detection position of the detection body changes (a phenomenon called temperature drift occurs) due to temperature changes of the differential transformer and the electric circuit (amplifier).
Further, in the magnetic sensor type as shown in Patent Document 2, the valve structure is complicated. Since a magnetic sensor is required, it is expensive. Before use, it is necessary to adjust the position of the magnet which is a magnetic sensor or a detection body. There are similar problems such as a change in the detection position of the detection body (a phenomenon called temperature drift occurs) due to a temperature change of the magnetic sensor.
Moreover, there is a difference between the position of the detection body where the magnetic sensor is turned on and the position of the detection body where the magnetic sensor is turned off (there is hysteresis). Furthermore, both of them have a problem that the sensitivity is poor because the spool in the sealed pressure resistant space is detected from the outside.

  In view of the above-mentioned problems, the subject of the present invention does not use expensive sensors and electric circuits. Simple structure and excellent durability. It is not necessary to adjust the position of the sensor and the detection body in the pre-use stage. Unlike magnetic sensors, the detection positions at ON and OFF are the same (no hysteresis). It is an object to provide a pilot check valve with a shock prevention mechanism and an operation detection function having features such that the detection position of a detection body does not change due to a change in temperature (no temperature drift).

Therefore, in the invention of claim 1, a valve body having an axial hole provided with a plurality of fluid passages,
A check valve body that is slidably inserted into an axial hole formed in the valve body and opens and closes the fluid passage;
Means for moving or positioning the check valve body;
A needle valve body slidably inserted into the check valve body;
A pilot check valve with a shock prevention mechanism equipped with
Extending at least one of the needle valve bodies, and a detector provided in the extended portion;
A ring member provided concentrically with the needle valve body so that the detection unit can enter and exit and does not interfere with the needle valve body;
Either the outer end surface of the ring member or the detection portion or the detection portion can be moved in the axial direction so as to be contactable at the same time so as not to interfere with the needle valve body except for the detection portion and concentric with the needle valve body. A ring-shaped contact member provided;
A spring for urging the contact member toward the detection unit or the ring member;
Have
The contact member is electrically connected to an electrical terminal having electrical conductivity and electrically connectable to the outside, and the ring member is electrically connected to a detection electrical terminal different from the electrical terminal, When the ring member and the contact member abut, the electrical terminal and the detection electrical terminal conduct through the ring member, and when the ring member and the contact member are separated, at least the ring member and the electrical The terminal is not electrically conductive.
According to the present invention, the needle valve body itself that is displaced integrally with the check valve body acts on the contact member to form an open / close switch, so that there is no need to detect from outside the sealed space, and the check valve body in the sealed space. Can be detected directly.
In the invention according to claim 2, when the check valve body is displaced along the axial hole, the tip portion is provided with a tip portion that becomes an overlap portion at a contact position with the valve body. ,
By adjusting the length of the overlap portion, it is possible to adjust the relationship between the timing at which the check valve body is actuated and the pressure fluid starts to flow and the timing at which the detection switch is switched. It is.
According to a third aspect of the present invention, when the overlap portion is provided larger than the gap, the contact member is moved after the check valve body is displaced, and the fluid passage after the ring member and the contact member are not in contact with each other. It is only necessary that the timing of the detection switch can be taken by communicating.

According to the present invention, regarding a check valve body or a needle valve body of a pilot check valve with a shock prevention mechanism, the detection switch is turned on when closed, and the detection switch is turned off when opened by self-port pressure or a piston. It became possible to take out.
Therefore, when the check valve body or needle valve body is in the closed state, the hydraulic actuator does not operate, so it is possible to transmit information that is “safe”, and when the check valve body is open, the hydraulic actuator is operating, so that “danger” can be transmitted. It becomes.
In addition, during sequence control, it is possible to confirm that the hydraulic actuator has been stopped and the position has been maintained by closing the check valve body or needle valve body (signal ON) and to enter the next operation. Good.

Embodiments of the present invention will be described with reference to the drawings. FIGS. 1 to 4 are longitudinal sectional views of main parts of a pilot check valve 30 with a shock prevention mechanism and an operation detection function according to the first embodiment of the present invention.
1 and 2, the same components as those in FIG. 10 are denoted by the same reference numerals, and detailed description thereof is omitted. The same applies to the following description.
As shown in FIG. 1, cases (housings) 31 a and 31 b are attached to both end faces of the valve main body 11 by screw members (not shown). The cases 31a and 31b are provided with stepped through holes 32a and 32b. The stepped through holes 32a and 32b include stepped annular recesses 34a and 34b larger than the outer diameter of the check valve bodies 21a and 21b at one end and stepped holes 35a and 35b at the other end. O-rings 36 are attached to the stepped annular recesses 34 and 34b, and the joint surfaces between the valve body 11 and the cases 31a and 31b are sealed.

The needle valve bodies 37a and 37b slidably inserted into the axial holes 23a and 23b have one end portions protruding from the check valve bodies 20a and 20b and engaging both end surfaces of the spool 17, The other end portion is directed into the stepped holes 35a and 35b, and detection convex portions (detection portions) 46a and 46b having step portions 38a and 38b are provided on the other end side of the needle valve bodies 37 and 37b. ing. Therefore, the needle valve bodies 37a and 37b include small diameter portions 39a and 39b that form step portions 38a and 38b. Contacts (contact members) 40a and 40b are slidably fitted to the small diameter portions 39a and 39b. The contacts 40a and 40b are pressed against the detection convex portions 46a and 46b by the elastic force of the springs 41a and 41b wound around the outer peripheral portions of the small diameter portions 39a and 39b. The small diameter portions 39a and 39b have a guide function for the springs 41a and 41b. Further, the detection convex portions 46a and 46b function so that the contacts 40a and 40b can move integrally with the needle valve bodies 37a and 37b.
In the stepped holes 35a and 35b, first spacers 43a and 43b, rings 44a and 44b, and second spacers 45a having the same hollow hole in the axial center of the needle valve bodies 37a and 37b from the stepped portions 42a and 42b. , 45b are sequentially disposed, and are pressed into the stepped holes 35a, 35b by the tips of the lids 24a, 24b to be clamped and fixed. The lids 24a and 24b are engaged with the valve body 11 by screw members (not shown).

The first spacers 43a and 43b are formed with recessed inlay portions 50a and 50b on the side surfaces thereof. Convex portions 51a, 51b, 52a, 52b fitted into the inner diameters of the concave inlay portions 50a, 50b of the first spacers 43a, 43b and the second spacers 45a, 45b on both end surfaces of the rings 44a, 44b. Is formed.
As a result, the rings 44a and 44b are sandwiched between the first and second spaces 43a, 43b, 45a and 45b along the axial direction and the direction perpendicular to the axis, thereby preventing contact between the rings 44a and 44b and the cases 31a and 31b. ing. The first and second spacers 43a, 43b, 45a, 45b are electrically insulating materials so that the rings 44a, 44b and the cases 31a, 31b are not electrically connected.

In the embodiment of the present invention, the electrical insulating material is a glass fiber reinforced polyamide 66 resin in view of mechanical strength, heat resistance, insulation, oil resistance, and the like. Accordingly, the rings 44a and 44b are electrically insulated from the cases 31a and 31b and the first and second spacers 43a, 43b, 45a and 45b.
Of course, the diameters of the hollow holes of the first spacers 43a and 43b and the rings 44a and 44b are formed so as not to interfere with the moving rods 37a and 37b. The second spacers 45a, 45b are cylindrical and are provided so as not to interfere with the contacts 40a, 40b and the springs 41a, 41b.

The contacts 40a and 40b are provided so as to be pressed against the detection convex portions 46a and 46b of the needle valve bodies 37a and 37b by the elastic force of the springs 41a and 41b. 2 is formed smaller than the inner diameter of the spacers 45a and 45b, and is in contact with outer end faces (contact surfaces between the contactor and the ring) 53a and 53b of the rings 44a and 44b.
When the detection convex portions 46a and 46b of the needle valve bodies 37a and 37b are inside the positions of the outer end faces 53a and 53b of the rings 44a and 44b, the contacts 40a and 40 are placed on the outer end faces of the rings 44a and 44b. When the projections 46a and 46b for detection of the needle valve bodies 37a and 37b are outside the positions of the outer end faces of the rings 44a and 44b, the contacts 40a and 40b are detected by the needle valve bodies 37a and 37b. It is provided so as to come into contact with the convex portions 46a, 46b.

The contact surfaces (outer side end surfaces) 53a, 53b of the rings 44a, 44b with the contacts 40a, 40b are not coated with an insulating coating, and the metal surfaces are exposed, so that the rings 44a, 44b and the contacts 40a, 40a, 40b is configured to be electrically conductive. The contacts 40a and 40b, which are conductors, are always in conduction with the cases 31a and 31b, which are also conductors, through springs 41a and 41b, which are also conductors, and the lids 24a and 24b.
Since the cases 31a and 31b are connected to the electrical terminals 56a and 56b of the connector 55a, the contacts 40a and 40b and the electrical terminals are always in conduction. When the check valve bodies 20a, 20b and the needle valve bodies 37a, 37b are closed, the contacts 40a, 40 have a clearance ΔL, for example, 58a, 58b (see FIG. 3) with respect to the detection convex portions 46a, 46b. The contacts 40a, 40b and the rings 44a, 44b are in contact with each other and are in a conductive state.

Communication passages 59a and 59b are formed in the lower positions of the connectors 55a and 55b of the cases 31a and 31b integrated with the valve body 11 in a direction substantially perpendicular to the axis of the stepped through holes 32a and 32b. In this case, the axial centers of the communication passages 59a and 59b are provided so as to substantially coincide with the center lines in the width direction of the rings 44a and 44b provided in the stepped through holes 32a and 32b.
Further, since the screw 60 is provided on the links 44a and 44b and the rotational direction position of the screw 60 is provided on the center line of the communication passages 59a and 59b when viewed from above the communication passages 59a and 59b, the conductive rods 61a and 61b are attached. This can be easily performed when the screw is inserted into the communication passages 59a and 59b and screwed into the female screw 60. Stepped bushes 64a and 64b are inserted into the holes 62a and 62b and the holes 63a and 63b, and O-rings 66 are attached to the stepped portions 65a and 65b of the bushes 64a and 64b.

Further, through holes 67a and 67b are formed in the bushes 64a and 64b, O-rings 68 as seal members are mounted in the through-holes 67a and 67b, and seal plates 69a and 69b for stopping the O-rings 68 are provided. Provided in the holes 63a and 63b, the bushes 64a and 64b and the seal plates 69a and 69b are both made of glass fiber reinforced polyamide 66 resin, which is an electrical insulating material.
The conductive rods 61a and 61b pass through the through holes 67a and 67b and the hole of the O-ring 68, and the outer periphery of the conductive rods 61a and 61b is sealed with the O-ring 68 of the through holes 67a and 67b. Furthermore, since one end of the conductive rods 61a and 61b is provided on the outer peripheral surface of the rings 44a and 44b, the conductive rods 61a and 61b are electrically connected to the screw 60 in a conductive state. The terminals 57a, 57b are connected to the lead wires 70a, 70b.

Accordingly, the rings 44a and 44b, the conductive rods 61a and 61b, and the detection electrical terminals 57a and 57b are always electrically connected, while being insulated from the valve body 11, the cases 31a and 31b, and the like.
The check valve bodies 20a and 20b are provided so that the front end portions thereof have overlap portions ΔM, for example 71a and 71b (see FIG. 4), and are fitted into the valve seats 18a and 18b. , 71b can be adjusted to adjust the relationship between the timing at which the check valve bodies 20a, 20b are activated and the pressure fluid starts to flow and the timing at which a detection switch (not shown) is switched. At this time, the needle valve bodies 37a and 37b are engaged with the end faces of the inner openings of the check valve bodies 20a and 20b.

  The pilot check valve 30 with a shock prevention mechanism and an operation detection function according to the first embodiment reliably provides a detection switch for an external device (not shown) when the check valve bodies 20a and 20b are closed (see FIG. 4). Therefore, the stepped portions 38a and 38b of the needle valve bodies 37a and 37b are set free so that the contacts 40a and 40b and the rings 44a and 44b are reliably in contact with each other. Specifically, the distal ends of the needle valve bodies 37a and 37b with respect to the length (distance) from the distal end face of the needle valve bodies 37a and 37b to the end faces of the contacts 40a and 40b loosely inserted into the small diameter portions 39a and 39b The length difference ΔL (gap) from the surface to the stepped portions 38a and 38b is set slightly shorter. (See Figure 3)

Therefore, the length from the tip surface of the needle valve bodies 37a, 37b to the stepped portions 38a, 38b and the length from the tip surface of the needle valve bodies 37, 37b to the end surfaces of the contacts 40a, 40b loosely inserted into the small diameter portions 39a, 39b. If the difference is ΔL (see FIG. 3), the check valve elements 20a and 20b are checked after the check valve elements 20a and 20b are opened until the detection convex portions 46a and 46b of the needle valve elements 37a and 37b press the contacts 40a and 40b. The valve bodies 20a and 20b need to be displaced by the difference ΔL. In this case, since the check valve bodies 20a and 20b are opened with the detection switch being ON, an incorrect signal is transmitted.
In the embodiment of the present invention, an overlap portion ΔM inscribed in the seat diameter of the valve seats 18a, 18b is formed on the seat surfaces of the check valve bodies 20a, 20b (see FIG. 4).
Further, for example, the overlap portion ΔM is set slightly longer than the difference ΔL (ΔL <ΔM). As a result, the pressure fluid flows when the check valve bodies 20a and 20b displace the overlap portion ΔM, and the detection switch is turned OFF at a time corresponding to the difference ΔL in the middle. Accordingly, since the detection switch is turned off before the pressure fluid starts to flow, for example, a “danger” signal can be transmitted.

  In the first embodiment of the present invention, the case where the overlap portion ΔM is set to be slightly longer than the difference ΔL (ΔL <ΔM) has been described. In the case of a small size that does not cause a problem, it is not necessary to set the overlap portion ΔM, and the combination of the values of ΔL and ΔM may be changed according to the situation.

The shock check mechanism and the pilot check valve 30 with the operation detection function according to the embodiment of the present invention are basically configured as described above. Next, the operation will be described with reference to FIGS.
FIG. 5 is an operation explanatory view showing a state in which the shock check mechanism and the pilot check valve 30 with the operation detection function are in an unloaded state. In FIG. 5, since the pressure fluid does not flow into the pilot check valve 30 with the shock prevention mechanism and the operation detection function, the pump (not shown) as the pressure supply source is stopped or the solenoid valve (not shown) is held in the neutral position. Yes. Therefore, the pilot check valve 30 with the shock prevention mechanism and the operation detection function is held in an unloaded state with the fluid passages 14 and 15 connected to the tank port.
Therefore, the check valve body 20a is pressed against the valve seat 18a by the spring force of the spring 21a and is seated on the valve seat 18a. Further, the needle valve body 37a is seated on the inner seat portion of the check valve body 20a. In this state, since there is a slight gap between the needle valve body 37a and the contact 40a in the axial direction, they are not in contact with each other.
The contact 40a is pressed against the ring 44a by the elastic force of the spring 41a, and the outer side end surface of the ring 44a is engaged with the end surface of the contact 40a.
That is, the contact 40a has conductivity and is electrically connected to the electrical terminal 56a of the connector 55a (see FIG. 2) that can be electrically connected to an external device (not shown). The terminal 57a (see FIG. 2) is electrically connected (detection switch ON).

In this state, when the solenoid check valve (not shown) is operated to bring the shock prevention mechanism and the pilot check valve 30 with an operation detection function into the state shown in FIG. 6, the fluid passage 14 communicates with the pump and the fluid passage 15 becomes the tank (not shown). Not connected). For this reason, since the pressure fluid acts on the check valve body 20a from the fluid passage 12, the check valve body 20a is displaced in the arrow X direction. As a result, the needle valve element 37a is also pushed by the check valve element 20a and displaced in the arrow X direction, and the stepped portion 38a of the needle valve element 37a displaces the contact 40a in the arrow X direction.
Therefore, since the contact 40a is separated from the ring 44a, the electrical terminal 56a and the detection electrical terminal 57a (see FIG. 2) are electrically insulated (detection switch OFF).

When the state shown in FIG. 5, that is, when the pilot check valve 30 with the shock prevention mechanism and the operation detection function is in an unloaded state, the solenoid (not shown) is switched to the opposite side to the state shown in FIG. In communication, fluid passage 15 is connected to the pump. For this reason, since the pressure of the fluid passage 15 is higher than the pressure of the fluid passage 14, the piston 17 moves in the direction of the arrow X, opens the needle valve 21a and releases the pressure of the fluid passage 12, and then the check valve body 20a. Force open. Therefore, the back flow from the fluid passage 12 to the fluid passage 14 is possible.
At this time, the stepped portion 38a of the needle valve body 37a presses the contact 40a in the arrow X direction. Accordingly, since the contact 40a is separated from the ring 44a, the electrical terminal 56a and the detection electrical terminal 57a (see FIG. 2) are electrically insulated (detection switch OFF).

  Although the above description of the operation has described the relationship between the check valve body 20a and the needle valve body 37a and the connector 55a, the relationship between the check valve body 20b and the needle valve body 37b and the connector 55b is the same. Omitted. In this case, the check valve body 20b and the needle valve body 37b can be displaced in the direction of the arrow Y to perform the same operation as the check valve body 20a and the needle valve body 37a.

FIG. 8 is a longitudinal sectional view of a pilot check valve 80 with a shock prevention mechanism and an operation detection function according to another embodiment of the present invention. In FIG. 8, the same components as those in FIGS. 1 and 2 are shown. Are denoted by the same reference numerals, and detailed description thereof is omitted.
The pilot check valve 80 with shock prevention mechanism and operation detection function shown in FIG. 8 is characterized in that the overlap ΔM = 0 of the check valve bodies 81a and 81b is set (see FIG. 9). In this case, when the spool 17 is in the neutral position, the contacts 40a, 40 have a clearance ΔL, for example, 58a, 58b (see FIG. 3) and do not come into contact with the detection convex portions 46a, 46b. This is the same as the previous embodiment.
According to the present invention, it is possible to take out a signal indicating that the detection switch is ON when the shock prevention mechanism and the check valve body of the pilot check valve are closed, and that the detection switch is OFF when opened by the self-port pressure or the pilot piston. it can.

It is principal part sectional drawing of the pilot check valve with a shock prevention mechanism and an operation | movement detection function which concerns on the 1st Embodiment of this invention. It is sectional drawing of the II-II line of FIG. FIG. 3 is an enlarged detail view of a detection step portion of the needle valve body of FIG. 2. FIG. 3 is an enlarged detail view of a tip portion of the check valve body of FIG. 2. It is operation | movement explanatory drawing of a pilot check valve with a shock prevention mechanism and an operation position detection function. It is operation | movement explanatory drawing of a pilot check valve with a shock prevention mechanism and an operation position detection function. It is operation | movement explanatory drawing of a pilot check valve with a shock prevention mechanism and an operation position detection function. It is principal part sectional drawing of the shock prevention mechanism which concerns on other embodiment of this invention, and the pilot check valve with an operation | movement detection function. FIG. 9 is an enlarged detail view of a tip portion of the check valve body of FIG. 8. It is a longitudinal cross-sectional view which shows schematic structure of the conventional modular type pilot check valve with a shock prevention mechanism.

Explanation of symbols

10 Modular pilot check valve with shock prevention mechanism 11 Valve body
12 to 16 Fluid passage 17 Piston 18a, 18b Valve seat 19a, 19b Axial hole 20a, 20b Check valve body 30, 80 Pilot check valve 31a, 31b with shock prevention mechanism and operation detection function 37a, 37b Needle valve body 38a, 38b Stepped portion 40a, 40b Contactor 43a, 43b First spacer 44a, 44b Ring 46a, 46b Detection convex portion 55a, 55b Connector 56a, 56b Electric terminal 57a, 57b Detection electric terminal 58a58ab Clearance (ΔL)
61a, 61b Conductive rods 71a, 71b Overlap part (ΔM)

Claims (3)

A valve body having an axial bore with a plurality of fluid passageways;
A check valve body that is slidably inserted into an axial hole formed in the valve body and opens and closes the fluid passage;
Means for moving or positioning the check valve body;
A needle valve body slidably inserted into the check valve body;
A pilot check valve with a shock prevention mechanism equipped with
Extending at least one of the needle valve bodies, and a detector provided in the extended portion;
A ring member provided concentrically with the needle valve body so that the detection unit can enter and exit and does not interfere with the needle valve body;
Either the outer end surface of the ring member or the detection portion or the detection portion can be moved in the axial direction so as to be contactable at the same time so as not to interfere with the needle valve body except for the detection portion and concentric with the needle valve body. A ring-shaped contact member provided;
A spring for urging the contact member toward the detection unit or the ring member;
Have
The contact member is electrically connected to an electrical terminal having electrical conductivity and electrically connectable to the outside, and the ring member is electrically connected to a detection electrical terminal different from the electrical terminal, When the ring member and the contact member abut, the electrical terminal and the detection electrical terminal conduct through the ring member, and when the ring member and the contact member are separated, at least the ring member and the electrical A pilot check valve with a shock prevention mechanism and an operation detection function, wherein the terminal is not electrically conductive. In the pilot check valve with shock prevention mechanism and operation detection function according to claim 1,
Shock check mechanism and operation detection characterized in that the check valve body is provided with a tip portion which becomes an overlap portion when the tip portion is in contact with the valve body when displaced along the axial hole. Pilot check valve with function. In the pilot check valve with a shock prevention mechanism and an operation detection function according to claim 1 or 2,
A pilot check valve with a shock prevention mechanism and an operation detection function, wherein the overlap portion is provided larger than the gap.

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