JPH08177676A - Solenoid valve - Google Patents

Abstract

PURPOSE: To facilitate mounting a solenoid valve in a fuel injection pump without performing positioning, by arranging an external thread part formed in the periphery of a housing, valve body receiving hole and an opening part of a fluid passage, in the solenoid valve, respectively with the same axial center serving as the center. CONSTITUTION: In a solenoid spill valve 25, an external thread part 26b formed in the periphery of a housing 26, valve body receiving hole 26a and an opening part of a fluid passage (lower opening part of fuel passage 28b, external wall opening part of fuel passage P) are arranged respectively with the same axial center Z serving as the center. Accordingly, in the case of mounting the solenoid spill valve 25 in a fuel injection pump, necessity for positioning the opening part of the fluid passage and the opening part of each spill passage in a pump side, in the direction of rotation, is eliminated, and the valve can be easily mounted by only screwing the external thread part 26b to a head part of the pump housing. On the other hand, by constituting a housing member of two members of the valve housing 26 and a valve guide 28, working can be facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve, and more particularly to a solenoid valve used as a solenoid fuel spill valve in a fuel injection pump of a diesel engine.

[0002]

2. Description of the Related Art An electromagnetic valve of this type is embodied as an electromagnetic spill valve attached to a fuel injection pump of a diesel engine (for example, Japanese Patent Publication No. 5-74709). FIG. 3 shows a characteristic portion of a conventionally known electromagnetic spill valve. In the electromagnetic spill valve 50 shown in FIG. 3, the housing member 51 is provided with a valve body 52 which is operated in the valve opening position or the valve closing position in accordance with energization of the electromagnetic driving member 53. In the housing member 51, a high pressure passage 54 for guiding high pressure fuel in a direction orthogonal to the moving direction of the valve body 52,
A low pressure passage 55 is formed for spilling the high pressure fuel to the low pressure side. A pin hole 56 for inserting a positioning pin (not shown) is formed on the bottom surface of the housing member 51.

The electromagnetic spill valve 50 constructed as described above is used in the pin hole 5 when it is assembled to the fuel injection pump.
The high-pressure passage 54 is positioned by the positioning pin inserted into the connector 6, and is tightened and fixed by the retaining nut 57.

[0004]

However, since the conventional electromagnetic spill valve 50 requires positioning in the rotational direction, auxiliary members such as a positioning pin and a retaining nut 57 are required, which increases the number of parts. There was a problem that the work process during assembly was complicated.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an electromagnetic valve capable of easily performing an assembling work.

[0006]

In order to achieve the above object, a solenoid valve according to a first aspect of the present invention is provided with a valve body which opens or closes in response to energization of an electromagnetic drive member, and a valve body which slides the valve body. A solenoid valve having a movably held housing member for guiding a fluid flowing from a high pressure side to a low pressure side in a direction orthogonal to a moving direction of the valve body, wherein the housing member is screwed to an attachment target. And a valve body accommodating portion formed on the same shaft center as the screw part, and one end for introducing the high-pressure side fluid is opened at a position corresponding to the shaft center, and the high-pressure side fluid is The gist is that the other end extending in a direction orthogonal to the moving direction of the valve body has a fluid passage opening on a predetermined same radius around the axis.

In the solenoid valve according to the second aspect of the invention, the gist is that the housing member is composed of a first housing member having the threaded portion and a second housing member forming the fluid passage.

[0008]

According to the electromagnetic valve of the first aspect, the threaded portion, the valve body accommodating portion, and the openings at both ends of the fluid passage are formed around the same axis. That is, the housing member can be attached by rotating in any direction around the axis. Therefore, when the solenoid valve is attached to, for example, a fuel injection pump of a diesel engine, it is not necessary to position the fluid passage and the fuel passage on the fuel injection pump side (attachment target side) in the rotational direction, and the conventional apparatus is used. Configurations such as positioning pins are omitted.

According to the second aspect of the present invention, by constructing the housing member with two members, the processing of each member is facilitated, and the assembling work is facilitated.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the electromagnetic valve of the present invention is embodied as an electromagnetic fuel spill valve for a diesel engine fuel injection pump will be described below with reference to the drawings.

FIG. 1 shows a schematic structure of a fuel injection control device using a face cam type fuel injection pump. Note that, in the fuel injection pump 1 of FIG. 1, only essential parts are shown, and the configuration of a vane feed pump or the like which should be on the left side of the drawing is omitted. In FIG. 1, a drive shaft 3 is arranged in a pump housing 2 of a fuel injection pump 1, and a pulsar 4 having a plurality of teeth on its outer peripheral surface is attached to the drive shaft 3. When the drive shaft 3 rotates in synchronization with the crankshaft (not shown) of the diesel engine, a feed pump (not shown) rotates and fuel is supplied to the fuel chamber 5.

A cam plate 6 is connected to the right end of the drive shaft 3 in the figure via a coupling (not shown). One side of the cam plate 6 (left side of the figure)
Is provided with the same number of face cams 6a as the number of cylinders of the diesel engine. A roller ring 7 is arranged between the pulsar 4 and the cam plate 6, and the roller ring 7
A plurality of cam rollers 8 facing the face cam 6a of the cam plate 6 are attached to the.

A head portion 2a is provided on the right side of the pump housing 2 in the drawing, and a cylinder 10 is provided in the head portion 2a. A plunger hole 11 is formed in the cylinder 10. A plunger 12 is slidably arranged in the plunger hole 11. The plunger 12 is supported by the cam plate 6 so as to be integrally rotatable. The cam plate 6 is constantly urged and engaged with the cam roller 8 by the plunger spring 13. Therefore, the cam plate 6 and the plunger 12 rotate as the drive shaft 3 rotates, and the face cam 6a
And the cam roller 8 engage with each other to reciprocate in the left-right direction in the drawing.

A pump chamber 14 is formed by the cylinder 10 and the end surface of the plunger 12, and suction grooves 15 for the number of cylinders are formed on the peripheral surface near the end of the plunger 12. When one of the suction grooves 15 communicates with the suction passage 16 provided in the cylinder 10 and the head portion 2a as the plunger 12 rotates, fuel is sucked from the fuel chamber 5 into the pump chamber 14. Further, as the plunger 12 moves to the right in the figure, the fuel sucked into the pump chamber 14 is pressurized, and the fuel is pumped to the injection passage 19 through the communication passage 17 and the distribution port 18. Then, the fuel is fed to the fuel injection nozzle 21 via the delivery valve 20 and injected from the nozzle 21 into the combustion chamber of the engine.

On the other hand, the fuel chamber 5 in the pump housing 2 is provided with a rotation speed sensor 22 which is attached integrally with the roller ring 7. The rotation speed sensor 22 is composed of an electromagnetic pickup coil and detects passage of teeth provided on the outer peripheral surface of the pulsar 4. That is, the rotation speed sensor 22 outputs a reference timing signal at a constant timing with respect to the plunger lift.

The head portion 2a of the pump housing 2
The spill passages 24a, 24b that connect the fuel chamber 5 and the pump chamber 14 are formed in the spill passages 24a, 24b.
An electromagnetic fuel spill valve (hereinafter referred to as an electromagnetic spill valve) 25 is arranged in the middle of b. For convenience, in the following description, 24a is referred to as a high pressure side spill passage and 24b is referred to as a low pressure side spill passage.

FIG. 2 is a sectional view showing the structure of the electromagnetic spill valve 25 in detail. In the electromagnetic spill valve 25 of FIG. 2, a male screw portion 26b is formed on the lower outer periphery of a valve housing 26 made of a non-magnetic material, and the male screw portion 26b causes the valve housing 26 to be screwed onto the head portion 2a of the pump housing 2. It is worn. Further, the valve housing 26 is formed with a valve body accommodating hole 26a having the same shaft center (hereinafter referred to as shaft center Z) as the male screw portion 26b, and the valve body accommodating hole 26a has a columnar shape. At the same time, a valve body 27 that opens downward in the drawing is housed. A valve guide 28 is inserted into the valve body 27 from its lower opening portion in a close contact state. Both the valve body 27 and the valve guide 28 have the same axis Z as the male screw portion 26b. Valve guide 2
8, a fuel passage 28b having a T-shaped cross section is formed,
One end thereof is opened at a position coinciding with the axis Z and the other end is opened at a position orthogonal to the axis Z.

Further, a tapered contact portion 27a is formed at the lower tip of the valve body 27, and a valve seat 28a is formed on the valve guide 28 facing the contact portion 27a. A compression coil spring 2 is provided in a spring chamber 27b formed in the valve body 27.
9 is provided, and the contact portion 27a and the valve seat 28a are provided.
The compression coil spring 29 constantly urges (hereinafter, referred to as a seat portion S) in a direction in which it separates. On the downstream side of the seat portion S, a fuel passage P is formed between the lower end surface of the valve housing 26 and the flange portion of the valve guide 28. The fuel passage P is intermittently opened on the circumference and communicates with the low pressure side spill passage 24b through the annular chamber Q. By providing the fuel passage P intermittently, the axial force at the time of tightening the screw is changed from the valve housing 26 to the valve guide 28.
I can tell you.

Therefore, the fuel introduced from the high pressure side spill passage 24a flows in the fuel passage 28b along the axis Z. After exiting from the fuel passage 28b, the low pressure side spill passage 2 passes through the gap of the seat portion S, the fuel passage P, and the annular chamber Q.
It flows to 4b. In this embodiment, the valve housing 26 and the valve guide 28 constitute the first and second housing members, and the fuel passage 28a and the fuel passage P correspond to fluid passages. In this case, the fluid passages (fuel passages 28a, P) are opened at a portion where one end (fuel passage 28a side) of the outer wall of the housing member (valve housing 26, valve guide 28) coincides with the axis Z, and the other end. The (fuel passage P side) is open on the same radius with the axis Z as the center.

On the other hand, an electromagnet 31 is provided above the valve housing 26, and a rod 33 extending in the vertical direction in the drawing is provided at the center of the electromagnet 31. The rod 33 is supported by a bush 34. The lower end of the rod 33 is in contact with the upper surface of the valve body 27, and an armature 35 is attached to the upper end of the rod 33. A cap member 3 made of a non-magnetic material is provided on the upper end of the valve housing 26.
6 is caulked. A stopper 37 for restricting the movable position of the armature 35 is attached to the cap member 36, and an energization signal from a drive circuit 41 (see FIG. 1) described later is input to the coil 32 constituting the electromagnet 31. A terminal 38 is attached. In this embodiment, the electromagnet 31, the rod 33 and the armature 35 constitute an electromagnetic drive member.

Therefore, in the electromagnetic spill valve 25 having the above structure, the valve body 27 is held at the valve open position (the position shown in FIG. 2) by the biasing force of the compression coil spring 29 when the electromagnet 31 is not energized. In this case, the seat S is separated and the fuel passages 28b and P are always opened. On the other hand, when the electromagnet 31 is energized, the armature 35 is attracted to the electromagnet 31, and the valve body 27 moves in the valve closing direction (downward in the figure) against the biasing force of the compression coil spring 29. As a result, the seat portion S abuts and the fuel passages 28b, P are closed.

On the other hand, in FIG. 1, an electronic control unit (hereinafter referred to as ECU) 40 is a CPU (central processing unit),
It is composed of a microcomputer including various memories and input / output circuits. The ECU 40 has a rotation speed sensor 2
The accelerator opening signal, the water temperature signal, etc. are input in addition to the input signal from the ECU 2, and the ECU 40 operates the engine based on these input signals (engine speed, accelerator opening,
Cooling water temperature, etc.) is detected. In addition, the ECU 40 controls the fuel injection amount according to the operating state of the engine,
A control signal for opening and closing the electromagnetic spill valve 25 is generated at a predetermined crank angle position, and the control signal is output to the drive circuit 41. Then, the drive circuit 41 energizes the electromagnet 31 of the electromagnetic spill valve 25 according to the control signal from the ECU 40.
De-energize.

Next, the operation of the fuel injection control system of this embodiment will be described. When the drive shaft 3 shown in FIG. 1 rotates due to the operation of the engine, the plunger 12 rotates with the rotation. At this time, since the face cam 6a is located at the descending portion of the cam, the plunger 12 moves leftward in the drawing. Then, the rotation of the plunger 12 causes the suction groove 15 and the cylinder 10 at the tip of the plunger 12 to rotate.
Of the fuel in the fuel chamber 5 through the suction groove 15 and the pump chamber 14 and the plunger 1
2 is sucked into the communication passage 17 inside. After the fuel is sucked, the suction passage 16 is closed as the plunger 12 rotates. Further, when the position of reaching the ascending portion of the cam, that is, the ascending portion of the face cam 6a of the cam plate 6 reaches the position of the roller 8, the plunger 12 moves rightward in FIG. 1 according to the cam lift amount.

Thereafter, when energization of the electromagnet 31 of the electromagnetic spill valve 25 is started at a predetermined valve driving timing, the armature 35 is attracted by the electromagnet 31 and the valve body 27 resists the biasing force of the compression coil spring 29. Move to the bottom of the figure.
As a result, the seat portion S abuts and the fuel passages 28b, P are closed. The fuel pressure in the pump chamber 14 rises due to the closing operation of the electromagnetic spill valve 25. At this time, the distribution port 18 is opened to one injection passage 19,
The fuel highly compressed in the pump chamber 14 is distributed to the distribution port 18,
It is pressure-fed to the fuel injection nozzle 21 through the injection passage 19 and the delivery valve 20. When the valve is closed, the high-pressure fuel acts on the valve body 27 from a direction orthogonal to the moving direction of the valve body 27, so that the valve body 27 operates without being affected by the high-pressure fuel, and the high-pressure fuel affects the valve body 27. Will never open.

When the electromagnet 31 of the electromagnetic spill valve 25 is de-energized when the desired injection amount is obtained, the attraction between the armature 35 and the electromagnet 31 is released, and the compression coil spring 2
The valve body 27 moves upward in the drawing by the biasing force of 9. Then, the fuel passages 28b, P are opened in accordance with the valve opening operation of the valve body 27, and the high pressure fuel in the pump chamber 14 flows into the gap of the seat portion S. That is, the high pressure fuel is spill passage 24a,
The fuel is spilled into the fuel chamber 5 through 24b and the fuel passages 28b and P. After that, the above operation is repeated every time the fuel is pumped from the pump chamber 14.

On the other hand, the electromagnetic spill valve 25 has the following features when it is assembled to the fuel injection pump 1. That is, as described above, the male screw portion 26b provided on the outer periphery of the valve housing 26, the valve body accommodation hole 26a, and the opening portion of the fluid passage (the lower opening portion of the fuel passage 28b, the outer wall side opening portion of the fuel passage P) are They are formed around the same axis Z. Therefore, when the electromagnetic spill valve 25 is attached to the fuel injection pump 1, it is not necessary to position the opening of the fluid passage and the openings of the spill passages 24a and 24b on the fuel injection pump 1 side in the rotational direction. Connect the male screw portion 26b of the valve housing 26 to the pump housing 2
The mounting work is completed by screwing the head portion 2a into the head portion 2a.
As a result, it is possible to omit the configuration such as the positioning pin as in the conventional device, and it is possible to easily carry out the assembly work.

In this case, by constructing the housing member with two members (valve housing 26, valve guide 28), each member can be easily processed. The present invention can be embodied as follows in addition to the above embodiment.

In the above embodiment, the fuel passage P on the low pressure side is formed on the circumference in the gap between the lower end of the valve housing 26 and the flange of the valve guide 28. However, this structure is modified as follows. Good.

(1) A fuel passage may be formed in advance (before assembly) in either the valve housing 26 or the valve guide 28. That is, in this case, the fuel passage is preliminarily formed in the outer wall of either the valve housing 26 or the valve guide 28.

(2) The valve guide 2 is connected to the fuel passage on the low pressure side.
It is also possible that the lower surface of 8 is opened in an annular shape and the fuel passage is communicated with the low pressure side spill passage 24b. Also in this case, it is not necessary to position the low-pressure passage in the rotational direction.

(3) The fuel passage P, which is intermittently provided to transmit the axial force of the screw, may be replaced with one or more holes.

[0032]

According to the solenoid valve of the first and second aspects, the excellent effect that the assembling work can be easily carried out is exhibited.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an outline of a fuel injection control device for a diesel engine.

FIG. 2 is a sectional view showing the configuration of an electromagnetic spill valve.

FIG. 3 is a cross-sectional view showing the structure of a conventional electromagnetic spill valve.

[Explanation of reference numerals] 2 ... Pump housing to be mounted, 25 ... Electromagnetic spill valve, 26 ... Valve housing as housing member (first housing member), 26a ... Valve body accommodation hole,
26b ... Male screw part, 27 ... Valve body, 28 ... Valve guide as housing member (second housing member), 28
b ... Fuel passage as fluid passage, 31 ... Electromagnet as electromagnetic driving member, 33 ... Rod as electromagnetic driving member, 3
5 ... Armature as electromagnetic drive member, P ... Fuel passage as fluid passage, Z ... Shaft center.

Claims (2)

[Claims] Claim: What is claimed is: 1. A valve body that opens or closes when an electromagnetic drive member is energized, and a housing member that slidably holds the valve body. An electromagnetic valve for guiding in a direction orthogonal to a moving direction of a valve body, wherein the housing member has a threaded portion for screwing to a mounting target and a valve body housing formed on the same axis as the threaded portion. Part, and one end for introducing the high-pressure side fluid is opened at a portion coinciding with the shaft center, and the other end for discharging the high-pressure side fluid in a direction orthogonal to the moving direction of the valve body is centered around the shaft center. And a fluid passage opening on the same radius of the solenoid valve. 2. The solenoid valve according to claim 1, wherein the housing member includes a first housing member having the threaded portion and a second housing member forming the fluid passage.