JPH03177671A - Solenoid valve - Google Patents

Abstract

PURPOSE:To stabilize an operating characteristic in an easy way by pressing a center pin in from the axial direction in the state of one part thereof protruding into a plunger, and regulating the effective stroke of the plunger between a core end face and a seat part according to the pressed-in margin of the center pin. CONSTITUTION:An operating oil lead-in port 16 and a lead-out port 17 are connected to a storage space 15 inside a valve body 1, and a plunger 18 for switching a seat part 30 communicated with the lead-out port 17 is disposed inside this storage space 15. A solenoid core 5 for sucking the plunger 18 against a return spring 23 is opposedly positioned at the base end of the plunger 18. A spacer 6 is further provided in such a way as to be engaged with the core 5 as well as to close the storage space 15, and a center pin 22 is pressed in with one part thereof protruding deeply into the plunger 18. The pressed-in margin of the center pin 2 is adjusted while being pressed by a jig from the lead-out port 17, thus adjusting the effective stroke of the plunger 18 easily and thereby preventing performance dispersion.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in, for example, electromagnetic unloader valves.

(Prior Art) As an unloader valve, there is an electromagnetic unloader valve that controls opening and closing of the valve using the suction force of a solenoid.

Since electromagnetic unloader valves can control load release using electrical signals via solenoids, they have excellent remote controllability, and their range of application is expanding.

(Problem to be solved by the invention) By the way, in such an electromagnetic unloader valve, it is extremely important to have little variation in the suction force of the solenoid when operating the valve in order to improve the stability of performance. .

Since the suction force of a solenoid is inversely proportional to the square of the distance, unless the initial distance between the core of the solenoid and the plunger attracted by it is adjusted accurately, the solenoid excitation 'Qk 'T' when the plunger starts operating t ; six
1. - +lk fp yi, ih A< k
＋' 7 く Iし pu 6) A: ffi+
＋ ＋＊ jk J, C changes significantly 9 Therefore, if you try to avoid this problem without changing the dimensional accuracy of this initial interval, the solenoid's excitation current should be set to a dimension higher than the designed rated value. It is necessary to set a large amount in advance to account for the variation in the current, but as the solenoid's suction force decreases with the square of the distance, the surplus current will actually become quite large. .

Therefore, an object of the present invention is to provide an electromagnetic valve that can improve stability of performance without requiring strict dimensional control.

(Means for Solving the Problems) The present invention connects an inlet and an outlet for hydraulic oil to a storage space inside a valve body, and directly or indirectly provides a seat portion that communicates with the outlet in the storage space. A plunger that opens and closes automatically is arranged, and the core of a solenoid located at the proximal end of the plunger that attracts the plunger against a return spring is opposed to the core of the solenoid and engages with the core and closes the storage space. A spacer is provided that is screwed until it contacts the stepped part of the valve body, and a center pin is press-fitted from the axial direction into the plunger with a part protruding, and the center pin is pressed into the core end face according to the press-fitting allowance. The effective stroke amount of the plunger between the seat parts is regulated.

(Function) Therefore, the plunger placed in the storage space of the valve body is moved in the axial direction by the center pin that is press-fitted with a portion protruding from the plunger.
In other words, since the stroke amount is regulated, the effective stroke amount can be arbitrarily set by adjusting the press-fit allowance through the outlet after the valve is assembled.

Thereby, the suction force of the solenoid applied to the plunger can be adjusted to a constant value with high precision, and variations in valve performance can be reliably prevented.

(Example) Hereinafter, it will be explained according to the drawings. As shown in the first embodiment shown in FIG. 1, a solenoid 3 is attached to a base end cylindrical portion 2 of a valve body 1.

In the solenoid 3, a corer is disposed passing through the inner periphery of the coil bobbin 4, and a disk-shaped spacer 6 is provided at the tip thereof. A threaded portion 7 is formed on the outer periphery of the spacer 6 and shines on the inner periphery of the proximal tube portion 2 of the valve body 1 until it comes into contact with a stepped portion 9. The end face of the corer protrudes somewhat from the end face of the spacer 6 and engages with the spacer 6 via a step 8.

A cylindrical case 10 is positioned outside the solenoid 3 and fitted on the outer periphery of the proximal tube portion 2. The end face of the case 10 is sealed with a cap 11, and the center of the cap 11 is The other end of the core 5 is inserted into the hole and fixed with a bolt 12. The coil bobbin 4 is pressed against the inner end surface of the spacer 6 via a spring 13.

A stepped cylindrical valve storage space 17i1L5 is formed inside the valve body 1, and a working oil inlet 16 is provided from the side to this storage space 15, and an outlet port is provided from the axial direction 1. 17 are connected.

11V 3+b Government P I C'; /71 Yamamoto 1. Shizu L+ M""p"/Knee' Jl I Q M
A disk 19 which is attached to the proximal end of the plunger 18 faces the corer of the solenoid 3 at a predetermined distance (plunger stroke).

A stepped through hole 20 is formed in the center of the plunger 18, and a center pin 20 is formed with a portion protruding from the tip side.
2 is press-fitted, and a return spring 23 is disposed on the proximal end side, urging the plunger 18 in a direction away from the corer.

A cylindrical spool 25 is disposed on the outside of the plunger 18 so as to be relatively freely slidable, and this spool 25 opens and closes a seat portion 30 communicating with the outlet 17.

A cylindrical spacer 26.2 is provided on the inner and outer peripheries of this spool 25.
7 is fitted.

A return spring 28 is in pressure contact with the base end of the spool 25, and this return spring 28 is connected to the storage space 15.
The spool 25 is supported by a retaining ring 29 that is engaged with the inner periphery of the spool 25, thereby urging the spool 25 toward the seat portion 30. In addition, the seat part 30 and the space ')EtnrWN,=
1 + feudal s: y-k plz k”Z1+L6
equipped.

An orifice 32 is formed on the side surface of the spool 25, and a port 33 is formed on the axis thereof.

A seat plate 34 is arranged inside this passage 33. In addition, a hole is formed in the center of each sheet plate) 31.34, and these sheet plates) 31.34
are held by springs 40 and 41.

The tip of the center pin 22 comes into contact with the inner end surface of the spool 25, thereby closing the hole of the seat plate 34 and the passage 33.

An annular chamber 35 that communicates with the introduction port 16 is formed on the outer periphery of the spool 25, and an internal chamber 36 that communicates with the annular chamber 35 through an orifice 32 is formed on the inner periphery of the spool 25. When the spool 25 is retracted from the seat portion 30, the inlet 16 and the outlet 17 are communicated with each other. The rear chamber 38 at the rear end of the spool 25 is always in communication with the internal chamber 36 via a vertical groove 39 formed on the outer periphery of the plunger 18.

The structure is as described above, and the operation will be explained next.

When solenoid 3 is not energized, plunger 1
8 is separated from the core 5 by a return spring 23, and the center pin 22 at the tip closes the opening 33 of the spool 25. Further, the spool 25 is also pressed against the seat portion 30 by the return spring 28, so that the inlet 16 and the outlet 17 are completely cut off, and there is no flow of hydraulic oil.

On the other hand, when the solenoid 3 is excited by electricity,
The core 5 is magnetized and an attractive force acts on the plunger 18.

Therefore, the plunger 18 is pulled against the return spring 23, and the center pin 22 is moved to the spool 25.
Open the doorway 33. As a result, the internal chamber 36 communicates with the low-pressure outlet 17 via the vent 33, so that the high-pressure hydraulic oil in the inlet 16 flows from the annular chamber 35 through the orifice 32 into the internal chamber 36, and then through the vent 33. 33 tends to flow out to the outlet 17.

Since the hydraulic oil is squeezed as it passes through the orifice 32, a large pressure difference is created between the annular chamber 35 and the internal chamber 36. Since the internal chamber 36 also communicates with the rear chamber 38,
The spool 25 has a high pressure annular chamber 35 and a low pressure internal chamber 36.
Due to the pressure difference between the back chamber 38 and the return spring 2
8 and move back away from the seat section 30.

As a result, the inlet 16 and the outlet 17 are connected through the annular chamber 35.
The high-pressure hydraulic oil is released and the load connected to the inlet 16 is released (unloader).

Incidentally, the stroke amount of the plunger 18 that is attracted by the solenoid 3 is the initial distance from the end surface of the plunger 18 to the end surface of the core 5, but the suction force exerted on the plunger 18 by the solenoid 3 increases according to the square of this distance. Change.

In particular, if the initial distance is larger than a preset distance, the suction force exerted on the plunger 18 will be significant. Therefore, the initial distance between the plunger 18 and the core 5 must be adjusted accurately.

However, in the present invention, this plunger stroke jl (initial interval) can be set to a predetermined value with high accuracy in a linear manner.

First, when assembling the valve, the center pin 22 is pressed into the tip of the plunger 18 so that it is slightly longer than its normal position, and in this state, the spool 25 and the plunger 18 are inserted into the valve body. Incorporate into.

Then, with the case 1o and coil bobbin 4 left in place, the spacer 6 into which the corer has been inserted is screwed onto the threaded portion 7 of the proximal tube portion 2 of the valve body 1.

Plunger 1 with a longer protrusion on the inner end surface of the spool 25
Since the center pin 22 of 8 is in contact with the spacer 6, the end face of the plunger 18 (the end face of the disk 9) butts against the end face of the spacer 6 when the spacer 6 is screwed together halfway, but it continues to come into contact with the stepped part 9. Tighten the spacers 6 until 11.

22 is further press-fitted into the plunger 18.

At the position where the spacer 6 is completely in contact with the stepped portion 9, the spool 25 is in pressure contact with the seat portion 30, and the plunger 18 is in pressure contact with the inside of the spool 25. At this stage, the plunger 18 cannot move at all. First, so to speak, the plunger stroke amount is correctly maintained at the zero point.

Next, insert a jig (not shown) into the spool 2 through the outlet 17.
5 from the tip surface, and while press-fitting the center pin 22 into the plunger 18, slowly push back the spool 25.

When the center pin 22 is press-fitted by a predetermined amount through the spool 25 in this way, the spacer 6 and the seat portion 3
0, the plunger 1 is connected to the spool 25.
8 is relatively movable, and this press-fitting allowance becomes the effective stroke amount of the plunger 18 after all.

As a result, the axial dimensions of the plunger 18, the spool 25, the corer, and the spool 25 of the plunger 18.
stroke amount and the seat portion 3 of the spool 25
Storage space 15 for determining the stroke amount relative to 0
Even if there are manufacturing variations in the mutual dimensions, etc., the plunger effective stroke amount (initial interval) for the corer can be easily and accurately set to any value.

Next, the embodiment shown in FIG. 2 will be explained.
It is a direct-acting type in which the seat portion 30 is directly opened and closed by the actuator 8, and does not include the spool 25 which is operated by differential pressure.

Therefore, when solenoid 3 is energized, plunger 1
8 is attracted, and the center pin 22 is attached to the seat plate 34.
The inlet port 16 and the outlet port 17 communicate with each other to allow the hydraulic oil to escape.

The effective stroke amount of the plunger 18 during assembly can be set by setting the center pin 22 slightly longer and press-fitting it into the plunger 18 by tightening the spacer 6, as described above. After adjusting the zero point, the center pin 22 may be press-fitted by a predetermined amount from the outlet 17 side using a jig.

(Effects of the Invention) As described above, according to the present invention, the plunger can be easily filled in the axial direction of the plunger (dimensions such as 1 length and the distance between the core and the seat part) even if the plunger is not filled in fR densely. The effective stroke amount can be accurately set to any value, and the valve's operating characteristics can therefore be stabilized very efficiently at low cost.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing the first embodiment of the present invention, No. 21J
is a sectional view of the second embodiment.

DESCRIPTION OF SYMBOLS 1... Half body, 2... Proximal tube part, 3... Solenoid, 5... Core, 6... Spacer, 9...
Stepped portion, 15...Storage space, 16...Inlet, 17.
- Outlet port, 18 - Plunger, 22... Center pin, 23... Return sphere link, 30... Seat section.

Claims (1)

[Claims] A hydraulic oil inlet and an outlet are connected to a storage space inside the valve body, and a plunger that directly or indirectly opens and closes a seat communicating with the outlet is arranged inside this storage space, and the base end of the plunger is The core of the solenoid which is located at and which attracts the plunger against the return spring faces the core, and is screwed together with the core until it comes into contact with the stepped part of the valve body so as to close the storage space. A spacer is provided, a center pin is press-fitted into the plunger from the axial direction with a part protruding, and the effective stroke amount of the plunger between the core end face and the seat part is regulated according to the press-fitting allowance of the center pin. An electromagnetic valve characterized by having the following configuration.