JP4561976B2 - Solenoid switching valve - Google Patents

Description

      The present invention relates to an electromagnetic switching valve. When the manual operation pin is operated, the spool is returned reliably by a spring member, and when the electromagnetic operation is performed, the manual operation pin is sucked and displaced by negative pressure. The present invention relates to an improvement in the structure of an electromagnetic switching valve that prevents the above-described problem.

Conventionally, an electromagnetic proportional solenoid 1 which is an electromagnetic switching valve of this type includes a coil assembly 2 in which a coil 4 wound around a bobbin 3 and yokes 5 and 6 constituting a coil outer peripheral circuit body are integrally formed, and the coil assembly. 2 has a tube assembly 11 and a cap 21 for connecting the assemblies 2 and 11 to each other. The tube assembly 11 is fixedly formed integrally with a pipe 12 that is mounted on the inner peripheral surface of the bobbin 3 and formed in a cylindrical shape, and a non-magnetic magnetic shielding member 13 on the distal end side of the pipe 12. It has an iron core 14 and a movable iron core 16 that is adsorbed by the fixed iron core 14 and slides inside the pipe 12.
The cap 21 is formed in a lid shape so as to close the opening of the tube assembly 11, and an internal thread 21 a that can be screwed to an external thread 12 b formed on the outer peripheral surface of the pipe 12 is formed on the inner peripheral surface of one end. A ring-shaped groove into which the end face of the pipe 12 is inserted is formed in the inner central portion, and a manual operation pin 22 is slidably mounted in the central portion via a spring member (not indicated) in the axial direction. (For example, refer to Patent Document 1).
Japanese Patent No. 3362307

However, in Patent Document 1, when the electromagnetic proportional solenoid 1 is manually operated, the manual operation pin 22 is pressed against the elastic force of the spring member using a tool or the like (not shown), and the electromagnetic proportional solenoid 1 is manually operated. When releasing the manual operation pin 22 from the tool or the like, the manual operation pin 22 is surely returned to the initial position by the elastic force of the spring member, and is prevented from being sucked and displaced by the negative pressure. However, since a space for providing a spring member is required, the length of the electromagnetic proportional solenoid 1 is extended as a whole. As a result, the electromagnetic proportional solenoid 1 becomes large, resulting in a high cost factor. It was.
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an electromagnetic switching valve that can be easily manually switched without using a spring member.

In order to achieve the above-mentioned object, the invention according to claim 1 includes a coil unit body on which a coil is mounted,
A sleeve body disposed in the coil body;
A connecting member that connects the coil body and the sleeve body;
With
A sleeve in which the sleeve body is formed in a cylindrical shape;
A plunger sliding in the sleeve;
A manually operated pin slidably supported in the scan rie Bed provided opposite to the plunger to press the sleeve,
Have
The hole formed in the sleeve into which the manual operation pin is inserted is formed such that the surface roughness on the backward limit side of the manual operation pin is rougher than the surface roughness on the forward limit side of the manual operation pin. And
According to the present invention, since the suction of the manual operation pin according to the negative pressure is prevented from leaking outside and the oil due to wear of the O-ring, is broken of the operating member is prevented.
Manual this case, the surface roughness of the retreat limit side is formed on 1.0～3.2MyumRa, surface roughness of the forward limit side when formed in 0.05～0.8MyumRa, when the manual operation Even if the operation pin is pushed in, it returns with a slight force, so that it is not necessary to provide a member such as a spring member for operating the electromagnetic switching valve.

The present invention, since the suction of the manual operation pin according to the negative pressure is prevented from leaking outside and the oil Joel wear of O-ring, breakage of the manually operated pin is prevented. In addition, since it returns with a slight force even when the manual operation pin is pushed during manual operation, it is not necessary to provide a member such as a spring member for operating the electromagnetic switching valve, so that cost can be reduced and quality can be improved.

An electromagnetic switching valve 30 according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a schematic structure of an electromagnetic switching valve 30 according to an embodiment of the present invention and a state in which a manual operation pin 49 is retracted. 2 and 3 show a view for explaining an operation of the electromagnetic switching valve 3 0.
As shown in FIG. 1, the electromagnetic switching valve 30 basically includes a coil part 31 that generates a suction force and a valve part 32 that controls a pressure fluid.

The coil part 31 is attracted by a coil part body 33 including a coil 34 for generating a magnetic field, a coil bobbin 35 and rings 37 and 38 serving as external magnetic paths, and a stopper 39 which is a fixed iron core when a magnetic field is applied. A plunger 40 having a function of a movable iron core, a guide 41 for supporting the plunger 40 and applying a magnetic field to the plunger 40, and a magnetic field flows from the guide 41 to the stopper 39 via the plunger 40. It is formed from a sleeve body 36 having a welded nonmagnetic material 42. In this case, the coil 34 is mounted on the coil bobbin 35 and is inserted into the coil bobbin 35 together with the links 37 and 38, and is inserted into a mold (not shown), and the coil part body 33 is formed by an injection molding machine. .

A rod 43 formed integrally with the movable iron core 40 is inserted into the fixed iron core 39 so as to be freely displaceable in an axial center portion thereof, and the rod 43 is attached to a sleeve 44 provided on the fixed iron core 39. that it has been supported.
Further, the boss portion 45 formed at one end portion of the fixed iron core 39 is joined to the valve main body 56 of the valve portion 32 by a screw mechanism.
When the coil body 33 and the sleeve body 36 are assembled, the sleeve 41 is inserted into the hole 33a of the coil body 33, and a fixing nut (connecting member) is attached to the screw portion 41a formed on the boss 46 of the sleeve 41. 47 is screwed. Boss into the hole 48 formed in the boss portion 46 of the sleeve 41 is provided a manual operation pin 49 is displaced in the axial direction, the該手dynamic operating pin 49 which engages in a recess 50 formed in the plunger 40 51 is provided. The manual operation pin 49 can displace the plunger 40 in the arrow Y direction with a tool (not shown).

As shown in FIG. 1, the electromagnetic switching valve 30 has a sliding resistance of the manual operation pin 49 when the manual operation pin 49 inserted in the hole 48 is displaced in the direction of the arrow X and completely returns (retreat limit). In order to secure the position of the retreat limit by enlarging the range, the area A of the hole 48 shown in FIG. 4 is in the state before finishing, and the lower limit surface roughness that does not affect the sealing performance of the O-ring 52 is For example, it is processed into 1.0-3.2 micrometers Ra (refer JIS standard B0601). For this reason, even if the pressure in the plunger 40 becomes a negative pressure, the manual operation pin 49 is not displaced by the sliding resistance.
On the other hand, as shown in FIG. 3, from a state in which該手dynamic operating pin 49 is displaced in the direction of arrow Y by operating the manual operation pin 49 is fully advanced (advance limit) as shown in FIG. 2,該手dynamic operation When the pin 49 is completely returned by the elastic force of the spring member 62, in order to reduce the sliding resistance of the manual operation pin 49, the range B portion of the hole 48 shown in FIG. The surface roughness to which the manual operation pin 49 is reliably returned by the elastic force of 62 is processed to, for example, 0.05 to 0.8 μm Ra (JIS standard B0601).

  For this reason, as shown in FIG. 4, the entire inner surface of the hole 48 is mirror-finished by burnishing after the reaming. Thereby, the surface roughness of the range A part and the range B part of the hole 48 is ensured to 1.0 to 3.2 μmRa and 0.05 to 0.8 μmRa, respectively, as described above.

In the valve portion 32, a spool 57 is slidably inserted into a valve body 56 which is a housing. The spool 57 is formed with first lands 58 and second lands 59 in the axial direction, and retainers 60a and 60b in the vicinity of both ends. A spring member 62 is fitted into the small diameter shaft end 61 of the retainer 60 b and the spool 57. One end of the spring member 62 engages with a spacer 63 inserted through the shaft end 61, and the other end is loaded in a recess 65 of a plug 64 screwed into the valve body 56. When de-excited, the spool 57 is displaced in the arrow X direction (retracted) by the elastic force of the spring member 62.
A semicircular (not shown) groove communicates with the first land 58 and the second land 59 in the circumferential direction, and the groove has a function of adjusting a set flow rate opening degree of the spool 57.
The port hole 66 formed in the valve body 56 is for connection to a hydraulic source (not shown), and the port hole 67 is for connection to an oil tank (not shown). The port holes 68 and 69 are ports connected to an actuator (not shown).

The electromagnetic switching valve 30 according to the embodiment of the present invention is basically configured as described above, and its operation will be described with reference to FIGS.
First, the operation when the manual operation pin 49 is not operated, that is, the operation of the electromagnetic switching valve 30 when the manual operation pin 49 is positioned in the backward limit will be described.
FIG. 1 is an operation explanatory view in the retreat limit in which the manual operation pin 49 is not operated, and the spool 57 is held in the neutral position by the elastic force of the spring member 62. In this state, the port hole 67 communicated with the tank flows through a gap (not shown) of the rod 43 formed in an oval cross-sectional shape (not shown) and the liquid chamber 39a in the stopper 39 and the plunger 40. The groove 40a and the liquid chamber 40b are connected. Here, since the port hole 67 communicates with the tank when used in general, the pressure of the pressurized fluid hardly rises and often becomes a negative pressure momentarily by switching other valves.

Next , when the coil 34 is energized to operate the electromagnetic switching valve 30, the plunger 40 is displaced in the arrow Y direction. For this reason, the pressure fluid in the liquid chamber 40 b of the stopper 40 passes through the groove 40 a and moves to the liquid chamber 39 a of the plunger 39. In this case, when the pressure fluid flows through the groove 40a, the liquid chamber 39a is lower than the liquid chamber 40a in proportion to the fluid resistance of the pressure fluid, and thus the frequency of the liquid chamber 39a becoming negative pressure increases.
On the other hand, the size of the diameter of the hole 48 into which the manual operation pin 49 is inserted makes the sliding resistance of the manual operation pin 49 as small as possible and the machine of the groove 53 (see FIG. 5) in which the O-ring 52 is mounted. Although it is set depending on the mechanical strength and the size of the O-ring 52, it is generally formed to have a diameter of 6 mm. For this reason, when the entire inner peripheral surface of the hole 48, that is, the range A portion and the range B portion are finished to a surface roughness of about 0.2 μmRa, for example, the sliding resistance of the manual operation pin 49 with the O-ring 52 inserted is 1 to 1. When the pressure becomes about 2N (Newton) and the pressure in the liquid chamber 39a becomes zero or less, the manual operation pin 49 is displaced in the direction of the arrow Y by the normal atmosphere.

On the contrary, when a surge pressure is applied to the port hole 67 or the coil 34 is turned off, the spool 57, the rod 43 and the plunger 40 are displaced in the direction of the arrow X by the elastic force of the spring member 62. The manual operation pin 49 is returned in the direction of the arrow X to a position where it comes into contact with the boss 46 (see FIG. 1).
Here, if the speed at which the manual operation pin 49 is displaced in the direction of the arrow X is large, a large impact force is applied to the groove 53 and the R portion 54 in which the O-ring 52 is mounted on the manual operation pin 49 as shown in FIG. Works. When the impact force is frequently applied to the manual operation pin 49 and the manual operation pin 49 is frequently displaced, external leakage of oil due to wear of the O-ring 52, and the manual operation pin 49 becomes the groove 53 and the R portion. May break at 54.

  However, in the electromagnetic switching valve 30 according to the present embodiment, the hole 48 of the boss portion 46 of the sleeve 44 into which the manual operation pin 49 is inserted is processed so that the surface roughness of the range A portion is 1.0 to 3.2 μmRa. Therefore, even if the sliding resistance of the manual operation pin 49 with the O-ring 52 inserted becomes 5 to 7N and the negative pressure of the liquid chamber 39a becomes maximum, the manual operation pin 49 is not displaced by the negative pressure. Breakage can be prevented.

Next, an operation when the manual operation pin 49 is operated, that is, an operation in which the manual operation pin 49 is positioned at the forward limit will be described.
FIG. 3 is an operation explanatory view showing a state in which the electromagnetic switching valve 30 is switched manually. The manual operation pin 49 is displaced in the direction of the arrow Y by a tool (not shown) and is pushed into the boss portion 46 to the maximum. For this reason, the plunger 40, the rod 43, and the spool 57 are displaced in the arrow Y direction, and the spring member 62 is compressed in accordance with the displacement amount of the spool 57.
When the manual switching action is stopped from this state, the operating force acting on the manual operation pin 49 is lost, and the plunger 40, the rod 43 and the spool 57 are moved by the arrow X by the biasing force of the compressed spring member 62. It is maintained in the state shown in displaced in the direction Figure 2. At this time, if the manual operation pin 49 has a large sliding resistance, the spring force of the spring member 62 does not displace in the arrow X direction, but the spring force of the spring member 62 displaces the manual operation pin 49 in the arrow X direction. The area B, which is the area, is processed to a surface roughness of, for example, 0.05 to 0.8 μm Ra by burnishing, so that the sliding resistance is about 1 to 2 N and is more than the elastic force of the spring member 62. Since it is smaller , the manual operation pin 49 is displaced in the arrow X direction.

When the electromagnetic switching valve 30 is manually operated, the manual operation pin 49 stops at the position shown in FIG. 2 , but when fluid pressure acts on the port hole 66 or excitation of the coil 34 of the electromagnetic switching valve 30. 1 is returned to the state shown in FIG. 1 by the inertial force of the plunger 40 displaced in the arrow X direction.

1 is a longitudinal sectional view showing a schematic structure of an electromagnetic switching valve according to an embodiment of the present invention. It is a longitudinal cross-sectional view which shows the state which the squirrel pool switched by manual operation of the electromagnetic switching valve of FIG. It is a longitudinal cross-sectional view which shows the state which the manual operation of the electromagnetic switching valve of FIG. 1 was stopped and the spool returned. It is a principal part enlarged view of the sleeve of FIG. FIG. 2 is an enlarged detail view of the manual operation pin of FIG. 1.

30 Solenoid switching valve
31 Coil part
32 Valve
33 Coil body
34 coils
36 Sleeve body
39 Stopper (Fixed iron core)
40 Plunger (movable iron core)
43 Rod
47 Fixing nut
48 holes
49 Manual operation pin
56 Valve body
57 spool
62 Spring member

Claims (2)

A coil body with a coil mounted thereon;
A sleeve body disposed in the coil body;
A connecting member that connects the coil body and the sleeve body;
With
A sleeve in which the sleeve body is formed in a cylindrical shape;
A plunger sliding in the sleeve;
A manually operated pin slidably supported in the scan rie Bed provided opposite to the plunger to press the sleeve,
Have
The hole formed in the sleeve into which the manual operation pin is inserted is formed such that the surface roughness on the backward limit side of the manual operation pin is rougher than the surface roughness on the forward limit side of the manual operation pin. An electromagnetic switching valve. The electromagnetic switching valve according to claim 1 ,
Before Symbol surface roughness of the retreat limit side is formed in 1.0～3.2MyumRa, electromagnetic switching valve that surface roughness of the forward limit side it is being formed on 0.05～0.8MyumRa.

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