JP2021156393A - Pilot-type solenoid valve - Google Patents

Abstract

To provide a pilot-type solenoid valve in which a piston and a valve seat are coaxially disposed, and the piston is moved along the axis.SOLUTION: A pilot-type solenoid valve 10 includes: a valve seat body 3 having a valve seat 3a and provided with a brazed outflow pipe 2; a piston 40 of which one end portion is brought into contact with and separated from the valve seat 3a; a plunger 70 provided with a pilot valve body 71 on one end portion; a main body 30 having a large-diameter portion 31 for mounting a valve chest 36, and a small-diameter portion 32 for guiding the plunger 70 slidably in an axial direction; a piston guide 50 formed by a machined body and guiding the piston 40 slidably in the axial direction; and a control portion 90 for driving the plunger 70. The piston guide 50 and the valve seat body 3 are respectively fitted to the large diameter portion 31 of the main body 30 to which an inflow pipe 1 is brazed. Thus distortion caused by effect of heat hardly occurs, and the piston and the valve seat can be coaxially disposed.SELECTED DRAWING: Figure 2

Description

The present invention relates to a pilot solenoid valve including a piston guide.

The pilot solenoid valve operates as an on-off valve by driving the piston slidably along the axial direction in conjunction with the axial movement of the plunger and separating and contacting the valve body provided on the piston with the valve seat. Is to do. Therefore, in the pilot solenoid valve, a piston guide for guiding the movement of the piston has been adopted so that the piston is driven coaxially with the valve seat to prevent valve leakage.

Further, in recent years, the main body parts used in the pilot solenoid valve have been shifting from the conventional machined parts to the stamped parts in order to reduce the parts cost.

Here, in the pilot type solenoid valve provided with the piston guide, the one in which the pressed parts are adopted for the valve body and the plunger tube (hereinafter, referred to as "conventional pilot type solenoid valve") is described in FIG. 6 of Patent Document 1, for example. It is disclosed in FIG. 7 and the like.

Japanese Unexamined Patent Publication No. 2015-4435

FIG. 6 is a cross-sectional view showing a conventional pilot solenoid valve 110. The conventional pilot solenoid valve 110 includes a valve body 120 having a valve chamber 126 and a valve seat 127a, a plunger tube 130, a piston 140 having a pilot valve chamber 144 and a pilot flow path 145, and a piston guide 150. Further, the conventional pilot solenoid valve 110 is a control unit provided on the outer peripheral portion of a plunger 170 holding the pilot valve body 171, a suction element 180 facing the plunger 170 via a coil spring 173, and a small diameter portion 132 of the plunger tube 130. (Not shown).

The inflow pipe 101 and the outflow pipe 102 are joined to the valve body 120 by brazing R and communicate with the valve chamber 126. Further, the upper end portion of the piston guide 150 includes a bent portion 154 that bends outward. Further, the lower end portion of the plunger tube 130 has a flange shape that bends outward, and is between the first flat portion 133, the second flat portion 134, the first flat portion 133, and the second flat portion 134. The connection portion 135 formed of is provided. Here, the bent portion 154 of the piston guide 150 is brought into contact with the connecting portion 135 of the plunger tube 130 to perform radial positioning and is joined to the second flat portion 134 by welding W.

Here, the piston 140 is slidably contained in the side wall 151 of the piston guide 150, and is separated from the valve seat 127a by the piston spring 160 disposed between the piston guide 150 and the piston 140. Be urged. An annular seal member 147 is disposed at the lower end of the piston 140, and the seal member 147 comes into contact with the valve seat 127a of the valve body 120 to seal the valve chamber 126.

In such a conventional pilot solenoid valve 110, it is very difficult to arrange the piston 140 coaxially with the valve seat 127a mainly due to the following two problems, and the piston 140 malfunctions or malfunctions. , There was a risk of valve leakage.

As the first problem, the piston guide 150 that guides the piston 140 and the valve body 120 in which the valve seat 127a is integrally formed are each composed of thin-walled stamped parts. Since it is generally difficult to obtain accuracy of pressed parts as compared with machined parts, the piston guide 150 positioned by the bent portion 154 and the valve seat 127a integrally formed with the valve body 120 are used. It was difficult to arrange each on the same axis (hereinafter referred to as "difficult to align the axes").

As a second problem, the piston guide 150, which is a pressed part, is welded to the connecting portion 135 of the plunger tube 130 via the bent portion 154. Therefore, at the time of this welding, the piston guide 150 may be affected by heat through the bent portion 154, and strain due to residual stress may occur (hereinafter, referred to as “strain due to heat effect”).

The present invention has been made in view of such a problem, and an object of the present invention is to provide a pilot solenoid valve in which a piston and a valve seat are arranged coaxially and the piston is moved along the same axis. do.

In order to solve the above problems, the pilot solenoid valve has a valve seat body to which an outflow pipe is brazed, and a piston having a pilot flow path and one end of which is separated from the valve seat. From a plunger that provides a pilot valve body that opens and closes the pilot flow path at one end, a large-diameter portion that provides a valve chamber, a main body that has a small-diameter portion that slidably guides the plunger in the axial direction, and a cutting body. The piston is provided in a piston guide formed and slidably guides the piston in the axial direction, and a control unit for driving the plunger, and the piston is provided in the large-diameter portion of the main body to which the inflow pipe is brazed. The piston guide and the valve seat body for accommodating the valve seat body are fitted to each other.

Further, in the pilot type solenoid valve, a groove portion formed continuously or separated in the circumferential direction is provided on the outer peripheral surface of the piston guide, and the piston guide is fitted to the large diameter portion of the main body. The main body may be plastically deformed and fixed to the groove portion of the piston guide.

Further, in the pilot solenoid valve, the valve seat body is fitted to the large diameter portion of the main body, and the valve seat body is locally melted with respect to the press-fitting allowance of the large diameter portion of the main body and the valve seat body. And it may be solidified and fixed.

Further, the pilot type solenoid valve includes a piston spring that urges the piston in a direction away from the valve seat, and the piston spring is provided at the other end of the piston with a flange portion and one end of the piston guide. It may be sandwiched between an annular inner protrusion provided on the portion.

Further, in the pilot type solenoid valve, the sliding surfaces of the piston and the piston guide may be provided so as to be separated or continuously provided in the axial direction.

According to the present invention, it is possible to provide a pilot solenoid valve in which the piston and the valve seat are arranged coaxially and the piston is moved along the same axis.

It is sectional drawing which shows the valve closed state of the pilot type solenoid valve provided with the piston guide which concerns on 1st Embodiment of this invention. It is an enlarged view of the pilot solenoid valve shown in FIG. 1, (a) is the region surrounded by the broken line II (a) of FIG. 1, (b) is the region surrounded by the broken line II (b), (c). ) And (d) represent the region surrounded by the broken lines II (c) and II (d), respectively. It is sectional drawing which shows the valve open state of the pilot solenoid valve shown in FIG. 1, (a) is the whole view of the pilot solenoid valve, (b) is surrounded by the broken line III (b) of (a). An enlarged view of the connection portion between the plunger tube and the first joint and the second joint is shown, respectively. It is explanatory drawing of the assembly process of the pilot type solenoid valve shown in FIG. (A) First joint connection process, (b) Plunger assembly process, (c) Plunger assembly process, (d) Piston assembly process, (e) Piston assembly process, (f) Second The process of assembling the joint, (g) the process of connecting the second joint, and (h) the process of assembling the control unit are represented. It is sectional drawing which shows the pilot type solenoid valve of the structure which does not have a piston spring which concerns on 2nd Embodiment of this invention, (a) is the mode that the sliding surface is separated in the axial direction, (b) is Each of the sliding surfaces represents a state in which they are continuous in the axial direction. It is sectional drawing which shows the conventional pilot type solenoid valve.

An embodiment of the present invention will be described in detail with reference to FIGS. 1 to 5. However, the present invention is not limited to the aspects of the present embodiment.

<Terminology>
In the description of the present specification and the scope of claims, "one end" and "the other end" mean "lower" and "upper" in the drawings.

(First Embodiment)
<About the configuration of the pilot solenoid valve>
The pilot solenoid valve 10 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 3. The pilot solenoid valve 10 is mainly composed of a main body 30, a piston 40, a piston guide 50, a piston spring 60, a plunger 70, a suction element 80, and a control unit 90 connected to the first joint 1A and the second joint 2A. It is composed of. Here, the first joint 1A is composed of an inflow pipe 1, and the second joint 2A is composed of an outflow pipe 2 and a valve seat body 3. Hereinafter, each configuration of the pilot solenoid valve 10 will be described.

The main body 30 is formed by press working, and has a cylindrical large-diameter portion 31 extending to one end side in the axial direction and a cylindrical small-diameter portion extending from the large-diameter portion 31 to the other end side in the axial direction. 32 and. A step portion 33 is formed at the joint portion between the large diameter portion 31 and the small diameter portion 32. As shown in FIG. 2B, the valve seat body 3 constituting the second joint 2A has a predetermined press-fitting allowance (fitting portion) L in the opening 34 on one end side of the large diameter portion 31. It is fitted and joined by welding W. The press-fitting allowance L in this embodiment is preferably 1 to 4 (mm). The valve seat body 3 includes a valve seat 3a and a valve port 3b, and an outflow pipe 2 into which a secondary side pressure on the low pressure side is introduced is brazed (brazed portion) R to the valve port 3b. Be joined. Further, a first joint 1A composed of an inflow pipe 1 into which a primary side pressure on the high pressure side is introduced is joined to the side opening 35 of the main body 30 by brazing (brazing portion) R to form a valve chamber 36. Communicate with.

Here, the inner diameter of the large diameter portion 31 of the main body 30 is set to be slightly smaller than the outermost diameter of the valve seat body 3. Therefore, as the press-fitting and fixing in the axial direction is advanced so that this press-fitting allowance L can be obtained, the valve seat body 3 and the main body 30 are positioned coaxially by sliding the opposite surfaces to each other. Can be placed in. As a result, the pilot solenoid valve 10 in the present embodiment can solve the above-mentioned first problem (difficulty in aligning the axes). Further, the welding W between the large diameter portion 31 and the valve seat body 3 is fixed by locally melting and solidifying with respect to the press-fitting allowance L in order to suppress distortion due to the influence of heat, for example, laser welding. Those that perform spot welding, etc. (those that provide welded parts). As a result, the pilot solenoid valve 10 in the present embodiment can solve the second problem (distortion due to the influence of heat).

The piston 40 is a machined part (cut body) formed from a block body by cutting and polishing (cutting) with high machining accuracy, and is a valve body 41 provided on one end side and a valve body 41 on the other end side. It includes a side wall 43 that extends and is provided with a flange portion 42 directed in the outer radial direction at the other end. Further, the piston 40 includes a pilot valve chamber 44 formed of a recess provided on the other end side, a pilot flow path 45 that communicates the central opening of the valve body 41 with the pilot valve chamber 44, and a pilot valve seat 46.

The piston guide 50 is a machined part (cut body) formed from a block body by cutting, polishing, or the like (cutting) with high machining accuracy, and includes a cylindrical portion 51 having a substantially hollow cylindrical shape. The cylindrical portion 51 has an annular inner protrusion 52 at one end and a groove 53 formed at the center of the outer peripheral surface in the axial direction so as to be continuous or separated in the circumferential direction. Here, with the piston spring 60 sandwiched between the annular inner protrusion 52 of the piston guide 50 and the flange portion 42 of the piston 40, the cylindrical portion 51 of the piston guide 50 is contained in the large diameter portion 31 of the main body 30. Is fitted. The piston spring 60 has a relatively large urging force that allows the valve body 41 to move in the direction away from the valve seat 3a even when there is no differential pressure between the primary side pressure and the secondary side pressure. It is composed of those with a weak spring constant. Here, the other end of the piston guide 50 is abutted against the stepped portion 33 of the main body 30 to perform axial positioning. Since the stepped portion 33 of the main body 30 is formed by press working, the corner portion of the stepped portion 33 has an R shape. Therefore, as shown in FIGS. 2C and 2D, the piston guide 50 has a tapered tip portion 51a1 and a notched tip portion 51a2 in order to avoid the R shape of the corner portion. ing. As a result, the amount of expansion and contraction of the piston spring 60 can be set to a predetermined value by reliably abutting the tip portions 51a1 and 51a2 of the piston guide 50 against the stepped portion 33 of the main body 30. In addition, the main body 30 is plastically deformed with respect to the groove 53 of the piston guide 50 by roll caulking, punching, or the like to form a fixed portion (plastically deformed portion) Fp.

In this way, the processing accuracy of the piston guide 50 is improved, and the piston guide 50 and the valve seat body 3 are fitted into the large diameter portion 31 in the same manner as the valve seat body 3. Dimension management for arranging on the same axis can be simplified. As a result, the pilot solenoid valve 10 in the present embodiment can solve the above-mentioned first problem (difficulty in aligning the axes) with respect to the valve seat body 3. Further, the piston guide 50 is formed by cutting, polishing, or the like (cutting), and is less likely to cause distortion due to residual stress as compared with pressed parts. Further, the fixing means between the piston guide 50 and the main body 30 utilizes the plastic deformation of the main body 30 instead of brazing which is affected by heat. Thereby, the second problem (distortion due to the influence of heat) can be solved.

The plunger 70 includes a pilot valve body 71 held on one end side and a recess 72 formed on the other end side. The plunger 70 is slidably guided in the small diameter portion 32 of the main body 30 in the axial direction. The coil spring 73 is sandwiched between the recess 72 of the plunger 70 and the suction element 80 fixed to the other end side of the small diameter portion 32 in a compressed state, and the plunger 70 is moved downward, that is, of the valve seat 3a. The piston 40 is urged in the direction.

The control unit 90 includes an electromagnetic coil 91 and a magnetic frame 92, is arranged on the outer peripheral portion of the small diameter portion 32 of the main body 30, and drives the plunger 70. The electromagnetic coil 91 includes a bobbin 93 that is mounted inside the magnetic frame 92 and has windings wound around it, and a mold resin 94 that molds around the bobbin 93. In the control unit 90, the fastening bolt 95 is screwed into the female screw 81 formed on the upper part of the attractor 80 via the bolt insertion hole 92a formed in the magnetic frame 92.

<About the operation of the pilot solenoid valve>
The operation of the pilot solenoid valve 10 having the configuration described above will be described. In the pilot solenoid valve 10, the primary side pressure (high pressure) is introduced through the inflow pipe 1, and the secondary side pressure (low pressure) is introduced through the outflow pipe 2. It is assumed that a differential pressure is generated between the pressure on the next side and the pressure on the next side.

(The state where the energization to the electromagnetic coil is cut off)
As shown in FIGS. 1 and 2, the plunger 70 moves in a direction away from the suction element 80 due to the urging force of the coil spring 73. As a result, the pilot valve body 71 held on one end side of the plunger 70 is seated on the pilot valve seat 46 formed above the pilot flow path 45 of the piston 40, and the pilot flow path 45 is closed.

Further, the plunger 70 further moves together with the piston 40 in a direction away from the suction element 80 while contracting the piston spring 60, so that the valve body 41 is seated on the valve seat 3a and formed on the valve seat 3a. The valve port 3b is closed. Here, a sliding surface is provided between the piston 40 and the piston guide 50. Specifically, the side wall 43 of the piston 40 and the annular inner protrusion 52 of the piston guide 50 provide the first sliding surface Ss1, and the flange portion 42 of the piston 40 and the cylindrical portion 51 of the piston guide 50. As a result, the second sliding surface Ss2 is provided. Therefore, the machining accuracy of the two sliding surfaces Ss1 and Ss2 is high, and the piston 40 is supported by the two sliding surfaces Ss1 and Ss2 separated in the axial direction. As a result, the piston 40 can be arranged coaxially with the valve seat 3a, and the piston can be slidably guided along the coaxial surface without tilting the piston. Therefore, the pilot solenoid valve 10 in the present embodiment can reliably perform the valve closing operation without causing malfunction of the piston 40 or valve leakage from the valve seat 3a.

Here, at positions corresponding to the first sliding surface Ss1 and the second sliding surface Ss2, an auxiliary flow path that constantly communicates the valve chamber 36 and the pilot valve chamber 44 is formed. The sub-flow path is an annular first sub-flow path Sf1 formed between the side wall 43 of the piston 40 and the annular inner protrusion 52 of the piston guide 50, and the flange portion 42 of the piston 40 and the piston guide 50. It is composed of an annular second sub-channel Sf2 formed between the cylindrical portion 51 and the cylindrical portion 51 of the above.

Therefore, in the state where the pilot flow path 45 and the valve port 3b are closed, the fluid of the inflow pipe 1 on the high pressure side passes through the first sub-flow path Sf1 and the second sub-flow path Sf2. It flows into the pilot valve chamber 44. As a result, in addition to the urging force of the coil spring 73, the high pressure of the pilot valve chamber 44 urges the valve body 41 in the direction of contacting the valve seat 3a.

(The state where the electromagnetic coil is energized)
As shown in FIG. 3, the plunger 70 moves in the direction of the suction element 80 against the urging force of the coil spring 73. As a result, the pilot valve body 71 held on one end side of the plunger 70 moves in a direction away from the pilot valve seat 46 formed on the upper part of the pilot flow path 45 of the piston 40, and opens the pilot flow path 45. It is in a valve state.

At this time, as shown in FIG. 3B, the high-pressure fluid in the pilot valve chamber 44 of the piston 40 is discharged to the outflow pipe 2 on the low-pressure side via the pilot flow path 45 (arrow E). reference). On the other hand, the fluid from the inflow pipe 1 is supplied to the pilot valve chamber 44 of the piston 40 via the first sub-flow path Sf1 and the second sub-flow path Sf2 (see arrow F). Here, in order to surely generate a differential pressure in the piston 40 and move the piston 40 in a direction away from the valve seat 3a, the supply flow rate to the pilot valve chamber 44 is made smaller than the discharge flow rate.

In this way, the pressure in the pilot valve chamber 44 that the piston 40 receives from above decreases, and a differential pressure is generated between the piston 40 and the primary pressure (high pressure) that the piston 40 receives from below, so that the piston 40 valves. The valve port 3b is opened by moving in the direction away from the seat 3a. Further, when the piston 40 moves in a direction away from the valve seat 3a while being supported by the two sliding surfaces Ss1 and Ss2, the stepped portion 33 of the main body 30 comes into contact with the flange portion 42 of the piston 40. By fulfilling the function of a stopper, the maximum opening degree of the valve body 41 is defined.

In the above description, it is assumed that a differential pressure is generated between the primary pressure and the secondary pressure. However, even when there is no differential pressure between the primary pressure and the secondary pressure, the piston spring 60 urges the piston 40 in the direction away from the valve seat 3a to open the valve. The operation can be performed reliably.

<Assembly process of pilot solenoid valve>
The assembly process of the pilot solenoid valve 10 will be described in order with reference to FIG.

(A) Connection Process of First Joint As shown in FIG. 4A, the first joint 1A composed of the inflow pipe 1 is brazed (brazed portion) R to the side opening 35 of the main body 30. Is joined by. Further, the suction element 80 is fixed to the other end side of the small diameter portion 32 of the main body 30 by welding or the like. Thereby, the influence of heat due to the brazing R can be limited only to the main body 30 and the first joint 1A.

(B) Plunger Assembly Process As shown in FIG. 4B, the plunger assembly 70A holds a spherical pilot valve body 71 on one end side of the plunger 70 by caulking or the like, and the other end of the plunger 70. It is assembled by accommodating the coil spring 73 in the recess 72 formed on the side.

(C) Plunger assembly process As shown in FIG. 4 (c), the plunger assembly 70A is inserted from the one-end side opening 34 of the main body 30 and is connected to the suction element 80 in the small diameter portion 32 of the main body 30. The coil spring 73 is arranged at a position where it is sandwiched between the coil springs 73.

(D) Piston Assembly Process As shown in FIG. 4D, the piston assembly 40A sandwiches the piston spring 60 between the flange portion 42 of the piston 40 and the annular inner protrusion 52 of the piston guide 50. It is assembled by doing. Here, the piston 40 and the piston guide 50 are machined parts (cutting bodies) formed from the block body by cutting and polishing (cutting) with high machining accuracy.

(E) Piston Assembling Step As shown in FIG. 4 (e), the piston assembly 40A is inserted through the one end side opening 34 of the main body 30, and the cylinder of the piston guide 50 is inserted into the large diameter portion 31 of the main body 30. The portions 51 are fitted, and the tip portions 51a1 and 51a2 of the piston guide 50 are abutted against the stepped portion 33 of the main body 30. Further, the large-diameter portion 31 of the main body 30 is plastically deformed with respect to the groove portion 53 of the piston guide 50 by roll caulking, punching, or the like to form a fixed portion (plastically deformed portion) Fp. As a result, the fixing means between the main body 30 and the piston guide 50 can suppress the thermal deformation of the piston guide 50 by utilizing the plastic deformation of the main body 30.

(F) Assembling Process of Second Joint As shown in FIG. 4 (f), in the second joint 2A, the outflow pipe 2 is brazed (brazed portion) R to the valve port 3b of the valve seat body 3. Assembled by joining. Thereby, the influence of heat due to the brazing R can be limited only to the valve seat body 3 and the outflow pipe 2.

(G) Connection Step of Second Joint As shown in FIG. 4 (g), a valve seat body 3 constituting the second joint 2A is fitted into a predetermined press-fitting allowance (fitting) in the opening 34 on one end side of the main body 30. The joint portion) L (see FIG. 2B) is fitted and joined by welding W. Here, as shown in FIGS. 4 (e) and 4 (g), the piston guide 50 and the valve seat body 3 are fitted into the large diameter portion 31 of the same main body 30 to be fitted with the piston guide 50. Dimension control for arranging the valve seat body 3 coaxially can be simplified. Further, the welding W is for locally melting and solidifying and fixing the press-fitting allowance L, for example, laser welding, spot welding, etc. (providing a welded portion), and the main body 30 and the valve seat. The thermal deformation of the body 3 can be suppressed.

(H) Assembling Step of Control Unit As shown in FIG. 4 (h), the small diameter portion 32 of the main body 30 is inserted inside the bobbin 93 of the control unit 90, and a bolt is attached to the female screw 81 of the suction element 80. The fastening bolt 95 is screwed through the insertion hole 92a.

As described above, in the assembly process of the pilot solenoid valve of the present embodiment, the piston 40 and the piston guide 50 are formed with high processing accuracy. Further, the use of the brazing R having a relatively large heat effect is limited to (a) the connection process of the first joint and (f) the assembly process of the second joint. Further, (e) the process of assembling the piston and (g) the process of connecting the second joint are particularly important for arranging the piston 40 and the valve seat 3a coaxially, so that the influence of heat is as small as possible. (Mating, roll caulking, punching, laser welding, spot welding, etc.) are used. As a result, the pilot solenoid valve 10 in the present embodiment can solve the first problem (difficulty in aligning the axes) and the second problem (distortion due to the influence of heat).

The assembly process of the pilot solenoid valve of the present embodiment is performed in the order of (a)-(h) shown in FIG. 4, but is not limited to this. For example, (a) a first joint connection process, (d) a piston assembly process, (e) a piston assembly process, (f) a second joint assembly process, (b) a plunger assembly process, ( c) The plunger assembling step, (g) the second joint connecting step, and (h) the control unit assembling step may be performed. In addition, when performing in this order, (a) in the connection step of the first joint, (a') the step of fixing the suction element is excluded, and (c) the step of assembling the plunger is performed, and then (a) a') The suction element fixing step will be performed. Further, the brazing timing in (a) the connection step of the first joint and (f) the assembly step of the second joint may be performed at the same time.

(Second Embodiment)
The pilot solenoid valves 11 and 12 having a structure without a piston spring according to the second embodiment of the present invention will be described with reference to FIGS. 5A and 5B.

First, the pilot solenoid valve 11 in an example of the second embodiment will be described with reference to FIG. 5A. The pilot solenoid valve 11 is different from the pilot solenoid valve 10 according to the first embodiment in that it is not provided with a piston spring 60 in order to have a specification that does not perform differential pressure operation. However, since the other basic configurations are the same as those in the first embodiment, the same members are designated by the same reference numerals, and duplicate description will be omitted.

Similar to the first embodiment, the piston 40 is separated in the axial direction and is supported by the sliding surfaces Ss1 and Ss2 having high machining accuracy. Therefore, the piston 40 is arranged coaxially with the valve seat 3a and is supported by the sliding surfaces Ss1 and Ss2. It can be guided slidably along the same axis without being tilted. Therefore, even in the pilot solenoid valve 11, the valve closing operation can be reliably performed without causing malfunction of the piston 40 or valve leakage from the valve seat 3a. Sub-flow passages Sf1 and Sf2 that constantly communicate the valve chamber 36 and the pilot valve chamber 44 are formed at positions corresponding to the sliding surfaces Ss1 and Ss2.

As a result, the pilot solenoid valve 11 can share all the parts with the pilot solenoid valve 10 according to the first embodiment, so that the productivity can be improved. Further, in the pilot solenoid valve 11, as in the pilot solenoid valve 10 in the first embodiment, the first problem (difficulty in aligning the axes) and the second problem (distortion due to the influence of heat) are solved. It can be resolved.

Next, the pilot solenoid valve 12 in another example of the second embodiment will be described with reference to FIG. 5 (b). The pilot solenoid valve 12 omits the flange portion of the piston 40'and the annular inner protrusion portion of the piston guide 50', and a single sliding surface Ss'where the piston 40'slides in the axial direction. It differs from the pilot solenoid valve 11 in that it is continuously provided. However, since the other basic configurations are the same as those of the pilot solenoid valve 11, the same members are designated by the same reference numerals, and redundant description will be omitted.

The piston 40'is a machined part (cut body) formed with high machining accuracy by cutting and polishing (cutting) from the block body, and the valve body 41'provided on one end side and the other end. A side wall 43'extending to the side is provided. Further, the piston guide 50'is a machined part (cutting body) formed from a block body by cutting and polishing (cutting) with high machining accuracy, and is a cylindrical portion 51'which has a substantially hollow cylindrical shape. Be prepared. The cylindrical portion 51'has a groove portion 53'formed continuously or separated in the circumferential direction at the central portion in the axial direction of the outer peripheral surface.

Since the piston 40'is continuous in the axial direction and supported by a single sliding surface Ss' with high machining accuracy, it is arranged coaxially with the valve seat 3a and tilts along this coaxial. It can be guided slidably without squeezing. Therefore, even in the pilot solenoid valve 12, the valve closing operation can be reliably performed without causing malfunction of the piston 40'or valve leakage from the valve seat 3a. A single subchannel Sf'that constantly communicates between the valve chamber 36 and the pilot valve chamber 44 is formed at a position corresponding to the single sliding surface Ss'.

As a result, in the pilot solenoid valve 12, the shapes of the piston 40'and the piston guide 50'can be simplified, so that the number of places where dimensional control is required can be reduced, and the productivity can be improved. Further, also in the pilot solenoid valve 12, the first problem (difficulty in aligning the axes) and the second problem (distortion due to the influence of heat) can be solved as in the pilot solenoid valve 11.

<Others>
The pilot solenoid valve of this embodiment can be applied to any fluid device and fluid circuit. Further, the present invention is not limited to the above-described embodiments, embodiments, and modifications described therein, and can be appropriately modified or modified without departing from the technical idea of the present invention.

10 Piston type solenoid valve 1A 1st joint 1 Inflow pipe 2A 2nd joint 2 Outflow pipe 3 Valve seat body 3a Valve seat 3b Valve port 30 Main body 31 Large diameter part 32 Small diameter part 33 Step part 34 One end side opening 35 side Square opening 40A Piston assembly 40, 40'Piston 41, 41' Valve body 42 Flange 43, 43' Side wall 44 Piston valve chamber 45 Piston flow path 46 Piston valve seat 50, 50'Piston guide 51, 51'Cylindrical part 51a1, 51a2 Tip 52 Announcing inner protrusion 53, 53'Groove 60 Piston spring 70A Plunger assembly 70 Plunger 71 Pilot valve 80 Suction element 90 Control unit L Press-fitting allowance R Brazing Sf1 First sub-flow path Sf2 First 2 sub-flow path Sf'single sub-flow path Ss1 first sliding surface Ss2 second sliding surface Ss' single sliding surface W welding

Claims (5)

A valve seat body with a valve seat and brazed outflow pipe,
A piston that has a pilot flow path and one end of which is in contact with the valve seat.
A plunger provided with a pilot valve body that opens and closes the pilot flow path at one end,
A main body having a large-diameter portion for providing a valve chamber, a small-diameter portion for slidably guiding the plunger in the axial direction, and a main body.
A piston guide formed from a cutting body and guides the piston so as to be slidable in the axial direction.
The control unit that drives the plunger and
With
A pilot type solenoid valve characterized in that the piston guide and the valve seat body are fitted to the large diameter portion of the main body to which the inflow pipe is brazed. A groove formed continuously or separated in the circumferential direction is provided on the outer peripheral surface of the piston guide.
The pilot solenoid according to claim 1, wherein the piston guide is fitted to the large-diameter portion of the main body, and the main body is plastically deformed and fixed to the groove portion of the piston guide. valve. The valve seat body is fitted to the large diameter portion of the main body, and is locally melted and solidified and fixed to the press-fitting allowance of the large diameter portion of the main body and the valve seat body. The pilot solenoid valve according to claim 1 or 2. A piston spring for urging the piston in a direction away from the valve seat is provided.
Any of claims 1 to 3, wherein the piston spring is sandwiched between a flange portion provided at the other end of the piston and an annular inner protrusion provided at one end of the piston guide. The pilot solenoid valve described in item 1. The pilot solenoid valve according to any one of claims 1 to 3, wherein the sliding surfaces of the piston and the piston guide are provided apart or continuously in the axial direction.

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