JP2009174619A - Solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solenoid valve not requiring high processing accuracy. <P>SOLUTION: A case has a step part formed on the housing side, a flange part formed in a fixing core and fixed by engaging with the step part, and an energizing member for energizing the fixing core to the step part side or the housing side in the opposite direction of a housing. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electromagnetic valve fixing structure.

Conventionally, the electromagnetic valve disclosed in Patent Document 1 has a case and a fixed core that is press-fitted and fixed to the case, and the plunger is driven by a movable core (armature).
JP 2000-49011 A

  However, in the above-described prior art, since the fixed core is press-fitted into the case, a high processing accuracy is required in the press-fitting portion, resulting in an increase in cost.

  The present invention has been made paying attention to the above problems, and an object thereof is to provide an electromagnetic valve that does not require high machining accuracy.

  In order to achieve the above-mentioned object, in the present invention, a case includes a step portion formed on the housing side, a flange portion formed on the fixed core, and fixed by engaging with the step portion, and a fixed core. And a biasing member that biases the step portion side or the housing side in the direction opposite to the housing.

  Therefore, an electromagnetic valve that does not require high machining accuracy can be provided.

  Hereinafter, the best mode for realizing the electromagnetic valve of the present invention will be described based on the embodiments shown in the drawings.

[System configuration of power steering system]
FIG. 1 is a system configuration diagram and a hydraulic circuit diagram of a power steering apparatus to which the electromagnetic valve of the present application is applied. 2 and 3 are diagrams showing the flow of hydraulic oil at the time of failure.

  When the driver steers the steering wheel 1, the pinion 3 is driven through the shaft 2, and the rack shaft 4 moves in the axial direction by a so-called rack and pinion mechanism to steer the front wheels. A torque sensor 5 is provided on the shaft 2 and outputs a torque signal to the control unit 8.

  The rack shaft 4 is provided with a power steering mechanism that assists the movement of the rack shaft 4 according to the steering torque of the driver. The power steering mechanism includes a motor M, a bidirectional pump P, and a power cylinder 6.

  The power cylinder 6 is defined in a first cylinder chamber 61 and a second cylinder chamber 62 by a piston 63 provided so as to be movable in the axial direction, and the first and second cylinder chambers 61, 62 are in the first and second passages 21. , 22 to connect to the pump P. The motor M is driven based on a command from the control unit 8, the pump P is rotated forward / reversely to supply hydraulic oil to the first and second cylinder chambers 61, 62, and the rack shaft 4 is moved in the axial direction to be steered. Generate assist force.

(Hydraulic circuit)
The first and second passages 21 and 22 are connected to the reservoir tank 7 via the first and second supply oil passages 28 and 29, and hydraulic oil is supplied by driving the pump. A switching valve 40 is provided in each of the first and second passages 21 and 22.

  The switching valve 40 is a valve that is mechanically opened / closed by a pressure difference between the first and second passages 21 and 22. When the first passage 21 is at a high pressure, the second passage 22 and the reservoir tank 7 are communicated. When the second passage is at a high pressure, the first passage 21 and the reservoir tank 7 are communicated.

  The first and second passages 21 and 22 are provided with third and fourth passages 23 and 24 that communicate the first and second passages 21 and 22 with each other. The third and fourth passages 23 and 24 are communicated / blocked with each other via the electromagnetic valve 100.

  In the third passage 23, third and fourth check valves 33 and 34 are provided with a connecting portion 25 with the electromagnetic valve 100 interposed therebetween. In the fourth passage 24, fifth and sixth check valves 35 and 36 are provided with a connection portion 26 with the electromagnetic valve 100 interposed therebetween.

  The third and fourth check valves 33 and 34 allow only the flow from the first and second passages 21 and 22 to the solenoid valve 100, respectively, and the fifth and sixth check valves 35 and 36 are first to the first solenoid valve 100, respectively. Only the flow to the second passages 21 and 22 is allowed. Therefore, if the solenoid valve 100 is in communication, the first and second passages 21 and 22 are connected via the third and sixth check valves 33 and 36 or the fourth and fifth check valves 34 and 35. Communicated.

  The solenoid valve 100 is a normally open solenoid valve, and is a fail-safe valve that is normally closed by the control unit 8 (see FIG. 1). Therefore, the valve is opened at the time of electrical failure and is in a communication state, and the first and second passages 21 and 22 are communicated via the third to sixth check valves 33 to 36 as described above, thereby ensuring manual steering. (See FIGS. 2 and 3).

  Further, first and second check valves 31 and 32 are provided in the first and second supply oil passages 28 and 29 to prevent backflow to the reservoir tank 7.

[solenoid valve]
4 is an axial sectional view of the solenoid valve 100, and FIG. 5 is a front view of the y-axis positive direction. In addition, let the axial direction of the solenoid valve 100 be a y-axis, and let the case 110 side be a positive direction.

  The electromagnetic valve 100 includes a case 110, a fixed core 120, an armature 130, a housing 140, and a valve portion 180. The case 110 has a bottomed cup shape that opens to the y-axis negative direction side (housing 140 side), and the opening extends in the radial direction and is fixed to the housing 140 by a bolt B.

  The fixed core 120 is a hollow member made of a magnetic material and having a y-axis as an axis. The fixed core 120 has a flange portion 121 extending to the outer peripheral side, and the housing insertion portion 123 on the y-axis negative direction side with respect to the flange portion 121 is inserted into the housing 140. The armature facing portion 122 on the y axis positive direction side with respect to the flange portion 121 is inserted into the case 110 together with the flange portion 121.

  The flange portion 121 and the armature facing portion 122 are accommodated in the inner periphery of the case 110, and the oil cap 131 is fitted to the armature facing portion 122. An armature 130 is accommodated in the oil cap 131 so as to be movable in the y-axis direction, and a coil 170 is provided on the outer peripheral side of the oil cap 131 to drive the armature 130 in the y-axis negative direction side.

  A rod 160 is provided on the inner periphery of the armature facing portion 122 and is urged toward the y-axis negative direction side by the first spring 171. In addition, the y-axis positive direction side of the rod 160 is abutted and locked to the armature 130, and moves to the y-axis negative direction side against the biasing force of the first spring 171 as the armature 130 moves in the y-axis negative direction. To do.

  The housing 140 has a valve hole 141, and a housing insertion portion 123 that is a side portion in the y-axis negative direction of the fixed core 120 is inserted into the valve hole 141. A valve portion 180 and a seat 190 are provided on the inner peripheral side of the housing insertion portion 123, and a second spring 172 is provided between the valve portion 180 and the seat 190.

  The seat 190 is fixed to the inner periphery of the housing insertion portion 123, but the valve portion 180 is provided so as to be movable in the y-axis direction. The y-axis negative direction side of the second spring 172 is locked by the seat 190, whereby the valve portion 180 is urged by the second spring 172 to the y-axis positive direction side.

  The valve portion 180 has a y-axis direction through hole 181, and a contact surface 182 is provided on the end surface on the y-axis positive direction side. When the rod 160 moves in the y-axis negative direction side as the armature 130 is driven in the y-axis negative direction, the tip portion 161 of the rod 160 comes into contact with the contact surface 182 and closes the y-axis direction through hole 181.

  The valve portion 180 is formed by a large-diameter portion 183 on the y-axis positive direction side and a small-diameter portion 184 on the y-axis negative direction side, and locks the second spring 172 at a step portion 186 between the large-diameter portion 183 and the small-diameter portion 184. To do. The large-diameter portion 183 is provided with substantially the same diameter as the inner periphery 124 of the housing insertion portion 123, whereby a second oil chamber D <b> 2 is formed between the small-diameter portion 184 and the inner periphery 124.

  In addition, a communication hole 126 that connects the inner periphery 124 and the outer periphery 125 of the housing insertion portion 123 is provided in a portion of the housing insertion portion 123 of the fixed core 120 where the y-axis direction position overlaps the small diameter portion 184. ing. The vicinity of the outer peripheral side opening 127 of the communication hole 126 is provided thinner than the other parts to form a recess 128.

  Thus, a first oil chamber D1 defined by the valve hole 141 and the recess 128 is formed. Since the first oil chamber D1 communicates with the inner periphery 124 at the y-axis negative direction side end through the communication hole 126, the first and second oil chambers D1 and D2 are always in communication.

  The sheet 190 is a hollow cylindrical member, and a sheet surface 191 is provided at the end on the y-axis positive direction side, and a communication hole 193 is provided at the center of the sheet surface 191. Further, the inner periphery 192 of the seat 190 is opened to the y axis negative direction side of the fixed core 120 to form a third oil chamber D3.

  The seat surface 191 is provided so as to be in liquid-tight contact with the y-axis negative direction side end portion 185 of the valve portion 180. Since the second oil chamber D2 and the third oil chamber D3 communicate with each other through the communication hole 193, the second and third oil chambers D2, D3 are blocked by the contact between the seat 190 and the valve portion 180.

  By driving the armature 130, the rod 160 moves in the negative y-axis direction, and the rod tip 161 comes into contact with the contact surface 182 of the valve unit 180. Thereby, the valve part 180 is pressed to the y-axis negative direction side.

  When the pressing force increases, the valve portion 180 moves to the y-axis negative direction side against the biasing force of the second spring 172, and the valve portion y-axis negative direction side end portion 185 and the seat surface 191 come into contact with each other. Accordingly, the second and third oil chambers D2 and D3 are blocked. Since the first and second oil chambers D1 and D2 are always in communication, the first and third oil chambers D1 and D3 are shut off, and the solenoid valve 1 is closed.

[Fixing case and fixed core]
The case 110 is formed of a main body part 111, an opening part 112, a step part 113, and a flange part insertion part 114. The main body 111 is on the positive side of the case 110 in the y-axis direction, and houses the armature facing portion 122 of the fixed core 120, the coil 170, the armature 130, and the oil cap 131.

  The opening 112 is provided with a larger diameter than the main body 111, and a step 113 is formed between the opening 112 and the main body 111. The step portion 113 is provided with substantially the same diameter as the flange portion 121 of the fixed core 120, and the flange portion 121 is inserted and fixed to the flange portion insertion portion 114 of the step portion 113 on the y-axis negative direction side.

  An annular elastic packing 200 is provided between the flange portion 121 and the step portion 113. A groove 121a is provided on the outer periphery of the flange 121 and on the end surface on the y-axis negative direction side, and the elastic packing 200 is provided in the groove 121a.

  The elastic packing 200 is provided by an elastic body and is in contact with the flange portion 121, the step portion 113, and the y-axis positive direction end surface 142 of the housing 140. The flange portion 121 is urged toward the y-axis positive direction side with respect to the housing 140 by elastic force, and the flange portion 121 is pressed against the step portion 113.

  As a result, the y-axis direction position of the flange portion 121 is fixed to the case 110 while eliminating backlash in the y-axis direction.

  The flange portion 121 is positioned with respect to the case 110 by the urging force, and the flange portion 121 (fixed core 120) can be fixed to the case 110 without being press-fitted.

  If it is press fit, it is necessary to provide high processing accuracy between the case 110 and the flange portion 121, but it is not necessary to increase the processing accuracy because the case 110 is fixed by the elastic force of the elastic packing 200 regardless of press fitting. Further, the sealing effect of the elastic packing 200 provided on the outer periphery of the flange portion 121 improves the sealing performance against external liquids and the like.

  Here, the oil cap 131 is fitted into an armature insertion portion 115 provided on the y-axis positive direction side of the case 110, and the radial gap a between the armature insertion portion 115 and the oil cap 131 is determined by the fixed core 120. It is assumed that it is smaller than the radial gap b between the flange portion 121 and the case 110.

  The magnetic field of the coil 170 drives the armature 130 stored in the oil cap 131 through the case 110. The radial gap between the oil cap 131 and the armature insertion portion 115 does not significantly affect the driving efficiency of the armature 130, but the driving efficiency is improved when the radial gap a between the armature insertion portion 115 and the armature 130 is small.

  The magnetic field of the coil 170 also acts on the flange portion 121 of the fixed core 120 via the case 110, but the radial direction between the case 110 and the flange portion 121 with respect to the radial gap a between the armature insertion portion 115 and the armature 130. The influence on the magnetic field formation by the gap b is small. Therefore, in consideration of assembling properties, the radial gap b between the case 110 and the flange 121 can be made larger than the radial gap a between the armature insertion part 115 and the armature 130.

  Therefore, the radial clearance b between the case 110 and the flange portion 121> the radial clearance a between the armature insertion portion 115 and the oil cap 131, so that the driving efficiency of the armature 130 is improved. In the case where the oil cap 131 is not provided, the driving efficiency is similarly improved by setting the radial clearance b between the case 110 and the flange portion 121> the radial clearance c between the armature 130 and the armature insertion portion 115.

[Effect of Example 1]
(1) A case 110 which is a step 113 formed on the housing 140 side;
A flange portion 121 formed on the fixed core 120 and fixed by engaging with the step portion 113;
The fixed core 120 has the urging member 200 that urges the fixed core 120 toward the step 113 in the direction opposite to the housing 140.

  Thereby, it becomes possible to fix by the elastic force of the elastic packing 200 irrespective of press-fitting, and it is not necessary to increase the processing accuracy, and the cost can be reduced.

  (2) The urging member 200 is an annular elastic packing 200. As a result, the urging member 200 also functions as a seal material, so that it is not necessary to provide a separate seal material, and the number of parts can be reduced.

  (3) The urging member 200 is provided on the outer edge of the flange portion 121. Thereby, the sealing performance with respect to an external liquid etc. can be improved.

  (4) The urging member 200 urges the flange portion 121 toward the step portion 113 in the direction opposite to the housing 140. Thereby, the fixed core 120 can be reliably fixed to the step portion 113 of the case 110.

(5) The case 110 having an armature insertion portion 115 at the end on the opposite side to the housing 140,
The radial gap c between the armature 130 and the armature insertion portion 115 of the case 110 is smaller than the radial gap b between the flange portion 121 of the fixed core 120 and the case 110.

  As a result, when the oil cap 131 is not provided, the radial clearance b between the case 110 and the flange portion 121> the radial clearance c between the armature 130 and the armature insertion portion 115, thereby improving the driving efficiency of the armature 130, Power saving and downsizing can be achieved.

(6) An oil cap is provided between the armature 130 and the case 110,
The oil cap is fixed to the fixed core 120,
The radial gap a between the oil cap and the armature insertion portion 115 is smaller than the radial gap b between the flange portion 121 of the fixed core 120 and the case 110.

  Accordingly, when the oil cap 131 is provided, the radial clearance b between the case 110 and the flange portion 121 is greater than the radial clearance a between the armature insertion portion 115 and the oil cap 131, and the driving efficiency of the armature 130 can be improved. .

(7) The elastic packing 200 (elastic holding member) formed between the outer periphery of the flange portion 121 and the case 110 is provided. The flange portion 121 (fixed core 120) can be fixed to the case 110 without being press-fitted by the elastic force of the elastic packing 200, so that it is not necessary to increase the processing accuracy and the cost can be reduced.
(Other examples)

  The best mode for carrying out the present invention has been described based on the embodiments. However, the specific configuration of the present invention is not limited to each embodiment, and the scope of the invention is not deviated. Design changes and the like are included in the present invention.

  In the first embodiment, the annular elastic packing 200 is used as the biasing member, but a disc spring 210 may be used as shown in FIG. In FIG. 6, the disc spring 210 is provided on the y axis positive direction side of the flange portion 121, and the flange portion 121 is biased toward the y axis negative direction side (housing 140 side).

  The disc spring 210 (elastic holding member) is formed between the outer periphery of the flange portion 121 and the case 110. Thereby, the flange part 121 is urged | biased to the housing 140 side (y-axis negative direction side), and the effect similar to said (1) and (3)-(6) can be acquired.

1 is a system configuration diagram and a hydraulic circuit diagram of a power steering device of the present application. It is a figure which shows the flow of the hydraulic oil at the time of failure. It is a figure which shows the flow of the hydraulic oil at the time of failure. 2 is an axial sectional view of the electromagnetic valve 100. FIG. 2 is a front view of the solenoid valve 100 in the y-axis positive direction. FIG. It is a figure which shows another Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Solenoid valve 110 Case 113 Step part 114 Armature insertion part 120 Fixed core 121 Flange part 130 Armature 131 Oil cap 140 Housing 150 Valve part 170 Coil 180 Valve part 200 Annular elastic packing (biasing member)
210 Disc spring (biasing member)

Claims (7)

A housing;
A case that opens to the housing side and is fixed and closed to the housing;
A fixed core accommodated on the inner peripheral side of the case and the inner peripheral side of the housing;
An armature housed between the case and the fixed core;
A coil for driving the armature;
A valve part opened and closed by the armature,
The case, a step formed on the housing side;
A flange formed on the fixed core and fixed by engaging with the step;
An electromagnetic valve comprising: a biasing member that biases the fixed core toward the stepped portion side or the housing side in a direction opposite to the housing. The solenoid valve according to claim 1,
The urging member is an annular elastic packing. The solenoid valve according to claim 1 or 2,
The urging member is provided on an outer edge of the flange portion. The electromagnetic valve according to any one of claims 1 to 3,
The solenoid valve according to claim 1, wherein the biasing member biases the flange portion in a direction opposite to the housing and toward the stepped portion. In the solenoid valve according to any one of claims 1 to 4,
The case, having an armature insertion portion at an end on the opposite side to the housing;
The electromagnetic valve according to claim 1, wherein a radial gap between the armature and the armature insertion portion of the case is smaller than a radial gap between the flange portion of the fixed core and the case. In the solenoid valve according to any one of claims 1 to 4,
The case, having an armature insertion portion at an end on the opposite side to the housing;
An oil cap is provided between the armature and the case,
The oil cap is fixed to the fixed core;
The electromagnetic valve according to claim 1, wherein a radial gap between the oil cap and the armature insertion portion is smaller than a radial gap between the flange portion of the fixed core and the case. A housing;
A case that opens to the housing side and is fixed and closed to the housing;
A fixed core accommodated on the inner peripheral side of the case and the inner peripheral side of the housing;
An armature housed between the case and the fixed core;
A coil for driving the armature;
A valve part opened and closed by the armature,
The case, a step formed on the housing side;
A flange formed on the fixed core and fixed by engaging with the step;
An electromagnetic valve comprising: an elastic holding member formed between an outer periphery of the flange portion and the case.

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