JP2023053967A - Damping force adjustment type shock absorber and solenoid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to maintain characteristics of a nonmagnetic member and maintain high magnetic flux density for a movable iron core between a first and a second fixed iron cores.

SOLUTION: A non-magnetic ring is provided between a first stator core and a second stator core constituting a main unit of a solenoid located on an inner peripheral side of a coil. The non-magnetic ring is joined between first and second fixed cores (first and second stator cores) by a brazing section so as to increase magnetic flux density of a magnetic circuit relative to a movable iron core (a plunger). The non-magnetic ring made of a non-magnetic material such as austenitic stainless steel has a larger or a smaller inner diameter than that of the first and the second stator cores, and a radial gap in a radial direction is formed relative to the plunger.

SELECTED DRAWING: Figure 3

COPYRIGHT: (C)2023,JPO&INPIT

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damping force adjustable shock absorber and a solenoid for damping vibration of a vehicle, for example.

Generally, a suspension system such as a semi-active suspension mounted on a vehicle is provided with a damping force adjustable shock absorber that variably adjusts the damping force according to the driving conditions, behavior, etc. of the vehicle. Also, among damping force adjustable shock absorbers, there is known one that uses a solenoid as an electromagnetic proportional actuator for variably adjusting the damping force. For example, Patent Document 1 discloses a solenoid of this type, which includes a coil that generates a magnetic force when energized, first and second fixed iron cores (stator cores) that are arranged on the inner peripheral side of the coil and are made of a magnetic material; A non-magnetic member axially connecting between the first and second fixed cores, and a movable core (a movable core ( plunger) is described.

Further, Patent Document 2 describes that a brazing means is used to join a non-magnetic member between the first and second fixed cores. In this case, for example, after the second fixed core and the non-magnetic member are joined by brazing, the inner peripheral surface thereof is machined to form a flat surface with no steps. He is trying to improve the slidability of a movable iron core by this. Furthermore, Patent Document 3 describes a configuration in which a thin portion is provided between first and second fixed cores to partially reduce the cross-sectional area of the magnetic path. Thereby, between the first and second fixed cores, the magnetic flux density passing through the movable core is increased, and the performance as a solenoid is improved.

JP 2014-73018 A JP 2009-127692 A JP 2017-118124 A

By the way, in the solenoid disclosed in the above patent document, a non-magnetic member is joined between the first and second fixed cores, and the non-magnetic member increases the magnetic flux density of the magnetic circuit with respect to the movable core. However, when the non-magnetic member is machined (for example, cutting the inner peripheral surface) after joining, the magnetic characteristics change due to processing strain, and the non-magnetic member is likely to be magnetized. Further, when a thin portion is provided between the first and second fixed cores to partially reduce the cross-sectional area of the magnetic path, the thinned portion reduces the mechanical strength of the entire fixed core, thereby reducing the durability. There is a problem that the life is shortened.

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the prior art described above. To provide a damping force adjustable shock absorber and a solenoid capable of maintaining a high damping force.

In order to solve the above-described problems, one embodiment of the present invention includes: a cylinder in which a working fluid is enclosed; a piston inserted into the cylinder to define the inside of the cylinder into a rod-side chamber and a bottom-side chamber; A piston rod connected to the piston and extending to the outside of the cylinder, a flow path through which the working fluid flows due to the movement of the piston rod, and a damping force adjustment valve provided in the flow path whose opening/closing operation is adjusted by a solenoid. and a damping force adjustable shock absorber comprising: a coil that generates a magnetic force when energized; first and second fixed iron cores provided on the inner circumference side of the coil; a non-magnetic member provided between first and second fixed cores and integrally fixed to the first and second fixed cores by brazing; A movable iron core disposed on the inner peripheral side of a non-magnetic member and provided movably in the axial direction, a shaft portion provided on the movable iron core, and first and second bushes supporting the shaft portion. A valve body of the damping force adjusting valve is provided at the end of the shaft portion on the side of the second fixed core, and the non-magnetic member has a large diameter or a small diameter, and the non-magnetic member uses a brazing material having a brazing temperature of 1000 degrees or more between the non-magnetic member and the conical protrusion provided at the end of the second fixed core. It is characterized in that it is joined to a second fixed core, and the axial end of the non-magnetic member and the second fixed core are in contact with each other.

A solenoid according to an embodiment of the present invention includes a coil that generates magnetic force when energized, first and second fixed iron cores provided on the inner peripheral side of the coil, and the first and second fixed iron cores. A non-magnetic member provided between and integrally fixed to the first and second fixed cores by brazing, and inner peripheral sides of the first and second fixed cores and the non-magnetic member a movable iron core provided movably in the axial direction; a shaft portion provided on the movable iron core; and first and second bushes supporting the shaft portion; The inner diameter of the non-magnetic member is larger or smaller than the inner diameter of the fixed core, and the non-magnetic member is brazed between the conical protrusion provided at the end of the second fixed core. It is characterized in that it is joined to the second fixed core using a brazing material having a bonding temperature of 1000° C. or more, and the axial end of the non-magnetic member and the second fixed core are in contact.

Further, one embodiment of the present invention includes a cylinder in which a working fluid is enclosed, a piston inserted into the cylinder and defining the inside of the cylinder into a rod-side chamber and a bottom-side chamber, and It comprises a piston rod extending to the outside of the cylinder, a flow path in which the working fluid flows due to the movement of the piston rod, and a damping force adjustment valve provided in the flow path whose opening/closing operation is adjusted by a solenoid. In the damping force adjustable shock absorber, the solenoid includes a coil that generates a magnetic force when energized, first and second fixed iron cores provided on the inner peripheral side of the coil, and the first and second fixed cores. a non-magnetic member provided between the iron cores and integrally fixed to the first and second fixed iron cores by brazing; inner circumferences of the first and second fixed iron cores and the non-magnetic member; a movable iron core disposed on the side of the movable iron core and provided movably in the axial direction; a shaft portion provided on the movable iron core; and first and second bushings supporting the shaft portion; A valve body of the damping force adjusting valve is provided at the end on the second fixed core side, and the non-magnetic member is interposed between a conical protrusion provided at the end of the second fixed core. It is characterized in that it is joined to the second fixed core using a brazing material having a bonding temperature of 1000° C. or more, and the axial end of the non-magnetic member and the second fixed core are in contact.

According to one embodiment of the present invention, it is possible to suppress changes in the characteristics of the non-magnetic member due to thermal effects, etc., and maintain a high magnetic flux density passing through the movable core between the first and second fixed cores. be able to.

1 is a longitudinal sectional view showing a damping force adjustable hydraulic shock absorber provided with a solenoid according to an embodiment of the present invention; FIG. 2 is an enlarged sectional view showing a damping force adjustment valve and a solenoid in FIG. 1; FIG. FIG. 3 is a cross-sectional view showing an enlarged solenoid with the damping force adjustment valve in FIG. 2 removed; FIG. 4 is a sectional view showing a state in which first and second stator cores and a non-magnetic ring of the solenoid in FIG. 3 are pre-assembled;

Hereinafter, a detailed description will be given of a case in which a damping force adjustable shock absorber and a solenoid according to an embodiment of the present invention are applied to a damping force adjustable hydraulic shock absorber, with reference to FIGS. 1 to 4. FIG.

In FIG. 1, a damping force adjustable hydraulic damper 1 (hereinafter referred to as hydraulic damper 1) is provided with a solenoid 33, which will be described later. This hydraulic shock absorber 1 includes an outer cylinder 2, an inner cylinder 4, a piston 5, a piston rod 8, a rod guide 9, a damping force adjusting device 17, and the like. In the following description, for example, one side in the axial direction of the outer cylinder 2 and the inner cylinder 4 is defined as the lower side, the lower side, or the lower end side, and the other axial side is defined as the upper side, the upper side, or the upper end side. and

A bottomed cylindrical outer cylinder 2 forming the outer shell of the hydraulic shock absorber 1 has a lower end closed by a bottom cap 3, and an upper end of the outer cylinder 2 is a crimped portion 2A bent radially inward. . A rod guide 9 and a seal member 10 are provided between the crimped portion 2A and the inner cylinder 4. As shown in FIG. On the other hand, an opening 2B is formed on the lower side of the outer cylinder 2 concentrically with a connection port 12C of the intermediate cylinder 12, which will be described later, and a damping force adjusting device 17, which will be described later, is attached facing the opening 2B. Also, the bottom cap 3 is provided with a mounting eye 3A that is mounted on the wheel side of the vehicle, for example.

An inner cylinder 4 is provided in the outer cylinder 2 coaxially with the outer cylinder 2 . The inner cylinder 4 has its lower end fitted to the bottom valve 13 and attached to it, and its upper end fitted to the rod guide 9 . A working liquid is sealed in the inner cylinder 4 as a working fluid. The working liquid is not limited to liquid oil or oil, and may be, for example, water mixed with an additive.

An annular reservoir chamber A is formed between the inner cylinder 4 and the outer cylinder 2, and the reservoir chamber A is filled with gas together with the oil. This gas may be air at atmospheric pressure, or a gas such as compressed nitrogen gas may be used. An oil hole 4A is formed in the radial direction of the inner cylinder 4 at a midway position in the length direction (axial direction) so that the rod-side oil chamber B always communicates with the annular oil chamber D. As shown in FIG.

The piston 5 is slidably fitted in the inner cylinder 4 . The piston 5 divides the interior of the inner cylinder 4 into a rod-side chamber (rod-side oil chamber B) and a bottom-side chamber (bottom-side oil chamber C). The piston 5 is provided with a plurality of oil passages 5A and 5B that allow the rod-side oil chamber B and the bottom-side oil chamber C to communicate with each other, and are spaced apart in the circumferential direction.

Here, a disk valve 6 on the extension side is provided on the lower end surface of the piston 5 . The extension side disk valve 6 opens when the pressure in the rod side oil chamber B exceeds the relief set pressure when the piston 5 slides upward during the extension stroke of the piston rod 8. The pressure is relieved to the bottom side oil chamber C side through each oil passage 5A. This relief setting pressure is set to a pressure higher than the valve opening pressure when the damping force adjustment device 17, which will be described later, is set to hard.

A contraction side check valve 7 is provided on the upper end surface of the piston 5. The check valve 7 opens when the piston 5 is slid downward in the contraction stroke of the piston rod 8, and closes otherwise. This check valve 7 allows the oil in the bottom side oil chamber C to flow through each oil passage 5B toward the rod side oil chamber B, and prevents the oil from flowing in the opposite direction. It is something to do. The valve opening pressure of the check valve 7 is set lower than the valve opening pressure when the later-described damping force adjusting device 17 is set soft, and the check valve 7 does not substantially generate damping force. The phrase "substantially no damping force is generated" means a force equal to or less than the friction of the piston 5 and the seal member 10, and does not affect the movement of the vehicle.

The piston rod 8 extends axially (upward and downward) inside the inner cylinder 4 . The lower end side of the piston rod 8 is inserted into the inner cylinder 4 and fixed to the piston 5 with a nut 8A or the like. Further, the upper end side of the piston rod 8 protrudes so as to extend to the outside of the outer cylinder 2 and the inner cylinder 4 via the rod guide 9 .

A stepped cylindrical rod guide 9 is provided on the upper end side of the inner cylinder 4 . The rod guide 9 positions the upper portion of the inner cylinder 4 at the center of the outer cylinder 2 and guides the piston rod 8 on the inner peripheral side thereof so as to be slidable in the axial direction. An annular seal member 10 is provided between the rod guide 9 and the caulked portion 2A of the outer cylinder 2. As shown in FIG. The seal member 10 is made by baking an elastic material such as rubber on an annular metal plate through which the piston rod 8 is inserted. to seal.

A lip seal 10</b>A as a check valve is formed on the lower surface of the seal member 10 so as to contact the rod guide 9 . The lip seal 10A is arranged between the oil sump chamber 11 and the reservoir chamber A, and prevents the oil or the like in the oil sump chamber 11 from flowing toward the reservoir chamber A side through the return passage 9A of the rod guide 9. It allows and prevents reverse flow.

Between the outer cylinder 2 and the inner cylinder 4, an intermediate cylinder 12 made of a cylindrical body is arranged. The intermediate cylinder 12 is attached, for example, to the outer peripheral side of the inner cylinder 4 via upper and lower cylindrical seals 12A and 12B. The intermediate cylinder 12 forms therein an annular oil chamber D extending so as to surround the entire outer circumference of the inner cylinder 4. The annular oil chamber D is an oil chamber independent of the reservoir chamber A. The annular oil chamber D always communicates with the rod-side oil chamber B through a radial oil hole 4A formed in the inner cylinder 4 . The annular oil chamber D serves as a flow path through which the hydraulic fluid flows as the piston rod 8 moves. A connection port 12C is provided on the lower end side of the intermediate tube 12 to which a cylindrical holder 20 of a damping force adjusting valve 18, which will be described later, is attached.

The bottom valve 13 is positioned on the lower end side of the inner cylinder 4 and provided between the bottom cap 3 and the inner cylinder 4 . The bottom valve 13 includes a valve body 14 defining a reservoir chamber A and a bottom-side oil chamber C between the bottom cap 3 and the inner cylinder 4, and a contraction-side disc valve provided on the lower surface side of the valve body 14. 15 and an extension side check valve 16 provided on the upper surface side of the valve body 14 . The valve body 14 is formed with oil passages 14A and 14B that allow the reservoir chamber A and the bottom-side oil chamber C to communicate with each other at intervals in the circumferential direction.

The contraction-side disk valve 15 opens when the pressure in the bottom-side oil chamber C exceeds the relief set pressure when the piston 5 slides downward in the contraction stroke of the piston rod 8, and the pressure at this time is is relieved to the reservoir chamber A side through each oil passage 14A. This relief setting pressure is set to a pressure higher than the valve opening pressure when the damping force adjustment device 17, which will be described later, is set to hard.

The extension-side check valve 16 opens when the piston 5 slides upward during the extension stroke of the piston rod 8, and closes otherwise. The extension-side check valve 16 allows the oil in the reservoir chamber A to flow through the oil passages 14B toward the bottom-side oil chamber C, and prevents the oil from flowing in the opposite direction. It is something to do. The valve opening pressure of the expansion side check valve 16 is set to a pressure lower than the valve opening pressure when the later-described damping force adjustment device 17 is set soft, and substantially no damping force is generated.

Next, the damping force adjusting device 17 for variably adjusting the damping force generated by the hydraulic damper 1 will be described with reference to FIG. 2 in addition to FIG. 2, the plunger 48 (operating pin 49) is moved to the position shown in FIG. It shows a state in which the pilot valve element 32 has moved to the left (that is, the valve closing direction in which the pilot valve body 32 is seated on the valve seat portion 26E of the pilot body 26).

As also shown in FIG. 1, the damping force adjustment device 17 is arranged so that its base end side (left end side in FIG. 1) is interposed between the reservoir chamber A and the annular oil chamber D, and its tip side (FIG. 1 (right end side) of the outer cylinder 2 is provided so as to protrude radially outward from the lower side of the outer cylinder 2 . The damping force adjustment device 17 includes a damping force adjustment valve 18 that generates a damping force with hard or soft characteristics by variably controlling the flow of oil from the annular oil chamber D to the reservoir chamber A, and the damping force adjustment valve 18. It includes a later-described solenoid 33 that adjusts the opening/closing operation of the valve 18 .

That is, the valve opening pressure of the damping force adjustment valve 18 is adjusted by a solenoid 33 used as a damping force variable actuator, whereby the generated damping force is variably controlled to hard or soft characteristics. The damping force adjustment valve 18 is a valve whose opening and closing operation is adjusted by a solenoid 33, and is a flow path (for example, between the annular oil chamber D and the reservoir chamber A) through which the working fluid flows due to the movement of the piston rod 8. is provided in

Here, the damping force adjusting valve 18 is provided with a substantially cylindrical valve case 19 having a proximal end fixed around the opening 2B of the outer cylinder 2 and a distal end protruding radially outward from the outer cylinder 2. a cylindrical holder 20 having a proximal end fixed to the connection port 12C of the intermediate cylinder 12 and a distal end forming an annular flange portion 20A and arranged with a gap inside the valve case 19; It includes a valve member 21 and the like that abut on the flange portion 20A.

The base end side of the valve case 19 forms an annular inner flange portion 19A extending radially inward, and the distal end side of the valve case 19 is a joint that joins the valve case 19 and a cover member 51 of a solenoid 33, which will be described later. A male threaded portion 19B to which the ring 52 is screwed. Between the inner peripheral surface of the valve case 19 and the outer peripheral surface of the valve member 21, and further between the inner peripheral surface of the valve case 19 and the outer peripheral surface of the pilot body 26, etc., an annular oil always communicates with the reservoir chamber A. The room is 19C.

The inside of the cylindrical holder 20 forms an oil passage 20B that communicates with the annular oil chamber D on one side and extends to the position of the valve member 21 on the other side. Between the flange portion 20A of the cylindrical holder 20 and the inner flange portion 19A of the valve case 19, an annular spacer 22 is provided in a pinched state. The spacer 22 is provided with a plurality of radially extending notches 22A serving as radial oil passages for communicating the oil chamber 19C and the reservoir chamber A. As shown in FIG. In this embodiment, the notch 22A for forming the oil passage is provided in the spacer 22. As shown in FIG. However, the inner flange portion 19A of the valve case 19 may be provided with notches radially for forming oil passages. With this configuration, the number of parts can be reduced by omitting the spacer 22 .

The valve member 21 is provided with a center hole 21A which is positioned at the center in the radial direction and extends in the axial direction. Further, the valve member 21 is provided with a plurality of oil passages 21B spaced apart in the circumferential direction around the central hole 21A. It is always in communication with the oil passage 20B of the shaped holder 20. In addition, on the other side (right side in FIGS. 1 and 2) end surface of the valve member 21, an annular recess 21C is formed so as to surround the other side opening of the oil passage 21B, and a radially outer side of the annular recess 21C. and an annular valve seat 21D on which a main valve 23, which will be described later, is seated. Here, each oil passage 21B of the valve member 21 is arranged between the oil passage 20B of the cylindrical holder 20 communicating with the annular oil chamber D and the oil chamber 19C of the valve case 19 communicating with the reservoir chamber A. It becomes a flow path through which the pressurized oil flows according to the degree of opening of 23 .

The main valve 23 is composed of a disk valve whose inner peripheral side is sandwiched between the valve member 21 and the large diameter portion 24A of the pilot pin 24 . The outer peripheral side of the main valve 23 is seated on and off the annular valve seat 21</b>D of the valve member 21 . An elastic seal member 23A is fixed to the rear side of the outer peripheral portion of the main valve 23 by means of baking or the like. The main valve 23 is opened by receiving pressure on the oil passage 21B side (annular oil chamber D side) of the valve member 21 and leaving the annular valve seat 21D. As a result, the oil passage 21B (on the side of the annular oil chamber D) of the valve member 21 communicates with the oil chamber 19C (on the side of the reservoir chamber A) via the main valve 23. It is variably adjusted according to the degree of opening.

The pilot pin 24 is formed in a stepped cylindrical shape, and has an annular large diameter portion 24A at its axially intermediate portion. The pilot pin 24 has a center hole 24B extending in the axial direction on its inner peripheral side, and a small diameter hole (orifice 24C) is formed at one end of the center hole 24B (the end on the cylindrical holder 20 side). . One end side (the left end side in FIGS. 1 and 2) of the pilot pin 24 is press-fitted into the center hole 21A of the valve member 21, and the main valve 23 is sandwiched between the large diameter portion 24A and the valve member 21. As shown in FIG. The other end side of the pilot pin 24 (the right end side in FIGS. 1 and 2) is fitted into the center hole 26C of the pilot body 26. As shown in FIG. In this state, an axially extending oil passage 25 is formed between the center hole 26</b>C of the pilot body 26 and the other end of the pilot pin 24 . This oil passage 25 communicates with a back pressure chamber 27 formed between the main valve 23 and the pilot body 26 . In other words, a plurality of oil passages 25 extending in the axial direction are provided in the circumferential direction on the side surface of the other end of the pilot pin 24 , and other circumferential positions are press-fitted into the center hole 26</b>C of the pilot body 26 .

The pilot body 26 is formed as a substantially bottomed cylindrical body having a cylindrical portion 26A with a stepped hole formed therein and a bottom portion 26B closing the cylindrical portion 26A. A bottom portion 26B of the pilot body 26 is provided with a center hole 26C into which the other end side of the pilot pin 24 is fitted. A protruding tubular portion 26D is integrally formed on the outer peripheral side of the bottom portion 26B of the pilot body 26 so as to extend toward the valve member 21 side (that is, the left side in FIGS. 1 and 2) over the entire circumference. The elastic seal member 23A of the main valve 23 is liquid-tightly fitted to the inner peripheral surface of the projecting cylindrical portion 26D, whereby a back pressure chamber 27 is formed between the main valve 23 and the pilot body 26. ing. The back pressure chamber 27 generates a pressure to press the main valve 23 in the valve closing direction, that is, in the direction in which the main valve 23 is seated on the annular valve seat 21</b>D of the valve member 21 .

The bottom portion 26B of the pilot body 26 is provided with a valve seat portion 26E located on the other end side (the right end side in FIGS. 1 and 2) on which a pilot valve body 32 (to be described later) separates and seats so as to surround the center hole 26C. It is Further, inside the cylindrical portion 26A of the pilot body 26, a return spring 28 that biases the pilot valve body 32 in a direction away from the valve seat portion 26E of the pilot body 26 is provided. A disk valve 29 constituting a fail-safe valve (when the valve element 32 is most distant from the valve seat 26E), a holding plate 30 having an oil passage 30A formed on the center side, and the like are disposed.

A cap 31 is fitted and fixed to the open end of the cylindrical portion 26A of the pilot body 26 with the return spring 28, the disk valve 29, the holding plate 30, etc. arranged inside the cylindrical portion 26A. The cap 31 has, for example, four notches 31A spaced apart in the circumferential direction. These notches 31A serve as flow paths for circulating the oil that has flowed to the solenoid 33 side through the oil passage 30A of the holding plate 30 to the oil chamber 19C (reservoir chamber A side) in the direction of arrow X shown in FIG. ing.

The pilot valve body 32 constitutes a pilot valve together with the pilot body 26 . The pilot valve element 32 is formed in a stepped cylindrical shape, and the tip portion that is seated and separated from the valve seat portion 26E of the pilot body 26 is a tapered portion. An actuation pin 49 of a solenoid 33, which will be described later, is fitted and fixed inside the pilot valve body 32, and the valve opening pressure of the pilot valve body 32 is adjusted according to the energization of the solenoid 33. ing. A flange portion 32A serving as a spring support is formed along the entire periphery of the pilot valve body 32 on the base end side thereof. The flange portion 32A contacts the disk valve 29 when the solenoid 33 is not energized (that is, when the pilot valve body 32 is displaced to the fully open position where it is most distant from the valve seat portion 26E). It regulates opening the valve beyond this.

Next, the solenoid 33 constituting the damping force adjusting device 17 together with the damping force adjusting valve 18 will be described with reference to FIGS. 2, 3 and 4. FIG.

The solenoid 33 is used in the damping force adjustable shock absorber to adjust the opening/closing operation of the damping force adjusting valve 18 . That is, the solenoid 33 used as a damping force variable actuator of the damping force adjustment device 17 includes a molded coil 34, a first stator core 36, a core lid 37, a second stator core 40, a non-magnetic ring 44, a plunger 48, and an operating pin. 49, a cover member 51, and the like.

The molded coil 34 is formed in a substantially cylindrical shape by integrally covering (molding) a coil 34A wound around a coil bobbin with a resin member 34B such as a thermosetting resin. A part of the molded coil 34 in the circumferential direction serves as a cable outlet (not shown) protruding outward in the axial direction or radial direction, and a wire cable (not shown) is connected to the cable outlet. The coil 34A becomes an electromagnet and generates magnetic force when power is supplied (energized) through a cable from the outside.

Of the resin member 34B of the molded coil 34, a seal groove 34C is formed over the entire circumference on a side surface (axial end surface) facing a cover member 51 (plate 51B), which will be described later. A seal member (for example, an O-ring 35) is mounted in the seal groove 34C. This O-ring 35 liquid-tightly seals between the molded coil 34 and the cover member 51 (plate 51B). As a result, dust including rainwater and muddy water can be prevented from entering the first and second stator cores 36 and 40 through between the cover member 51 and the molded coil 34 .

It should be noted that the coil employed in the present invention is not limited to the molded coil 34 comprising the coil 34A and the resin member 34B, and other coils may be employed. For example, a coil may be wound on a coil bobbin made of an electrically insulating material, and the outer circumference of the coil may be covered with an overmold (not shown) in which a resin material is molded from above (on the outer circumference side). .

The first stator core 36 constitutes a first fixed iron core provided on the inner peripheral side of the molded coil 34 (coil 34A). The first stator core 36 is made of a magnetic material such as low-carbon steel, carbon steel for machine structural use (S10C), or the like, and is formed as a cylindrical cylinder. The first stator core 36 has a small-diameter cylindrical portion 36A for joining formed on one axial side (left side in FIGS. 3 and 4), and a non-magnetic ring 44, which will be described later, is attached to the small-diameter cylindrical portion 36A. It is joined by the attaching part 45 . The inner diameter of the first stator core 36 is slightly larger than the outer diameter of a plunger 48 which will be described later, and the plunger 48 is axially movable within the first stator core 36 .

A tubular core cover 37 with a bottom is fitted to the other axial side of the first stator core 36 (on the right side in FIGS. 3 and 4). The core cover 37 is made of the same magnetic material as that of the first stator core 36 and formed into a cylindrical shape with a bottom, and closes the first stator core 36 from the other side in the axial direction (the left side in FIGS. 2 and 3). . A bottomed stepped hole 37A is formed inside the core lid 37, and the stepped hole 37A is provided with a first bush 38 for slidably supporting an operating pin 49, which will be described later. there is A seal groove 37</b>B (see FIG. 3 ) is provided along the outer circumference of the core lid body 37 between itself and the inner circumference of the first stator core 36 . An O-ring 39 as a sealing member is mounted in the seal groove 37B, and the O-ring 39 liquid-tightly seals between the first stator core 36 and the core lid 37 .

Further, the end surface of the bottom of the core lid body 37 is opposed to a plate 51B of the cover member 51, which will be described later, with a gap in the axial direction. This axial clearance has a function of preventing an axial force from being directly applied to the first stator core 36 from the plate 51</b>B side of the cover member 51 via the core lid 37 . Note that the core lid 37 does not necessarily have to be made of a magnetic material, and can be made of a rigid metal material, a ceramic material, or a fiber-reinforced resin material.

The second stator core 40 constitutes a second fixed iron core provided on the inner peripheral side of the molded coil 34 (coil 34A) away from the first stator core 36 to one side in the axial direction. The second stator core 40 is made of a magnetic material such as low-carbon steel, carbon steel for machine structural use (S10C), and has a stepped tubular shape, like the first stator core 36 (first fixed core). The second stator core 40 includes a cylindrical cylindrical portion 40A having a stepped hole 40F, which will be described later, on the inner peripheral side, and an annular cylindrical portion 40A extending radially outward over the entire circumference from the outer periphery on one side in the axial direction of the cylindrical portion 40A. It is formed as an integral body including a portion 40B and a cylindrical fitting portion 40C projecting from the outer peripheral side of the annular portion 40B toward one side in the axial direction (the damping force adjusting valve 18 side).

A cylindrical portion 40A of the second stator core 40 is provided with a circular concave portion 40D on the other side surface thereof axially facing a plunger 48, which will be described later. The concave portion 40D is formed as a circular groove having a diameter slightly larger than that of the plunger 48 so that a plunger 48, which will be described later, can be inserted into and retracted from the inside thereof by magnetic force. A conical protrusion 40E is provided on the other side of the cylindrical portion 40A so as to surround the periphery (outer periphery) of the concave portion 40D. The outer peripheral surface of the conical protrusion 40E is formed as a conical surface so that the magnetic characteristic between the cylindrical portion 40A of the second stator core 40 and the plunger 48 is linear. . That is, the conical projecting portion 40E projects in a cylindrical shape from the outer peripheral side of the cylindrical portion 40A of the second stator core 40 toward the other side in the axial direction, and the outer peripheral surface thereof extends from the one side in the axial direction to the other side (Fig. 3, The conical surface is tapered such that the outer diameter gradually decreases from the left side to the right side of the concave portion 40D shown in FIG.

Further, as shown in FIGS. 3 and 4, a stepped hole 40F is formed in the inner peripheral side of the cylindrical portion 40A, and the stepped hole 40F slidably supports an operation pin 49, which will be described later. A second bushing 41 is provided in a fitted manner. On the other hand, the annular portion 40B of the second stator core 40 is formed with a seal groove 40G in which a seal member (for example, an O-ring 42) is mounted on the other side surface facing the molded coil 34. A liquid-tight seal is provided between the coil 34 and the annular portion 40B.

As shown in FIG. 2, the cap 31 of the damping force adjustment valve 18 is fitted (fitted inside) to the inner peripheral side of the fitting portion 40C. Further, the valve case 19 of the damping force adjusting valve 18 is fitted (outside fitted) on the outer peripheral side of the fitting portion 40C. Furthermore, a seal groove 40H is provided over the entire circumference of the outer peripheral surface of the fitting portion 40C. An O-ring 43 as a sealing member is mounted in the seal groove 40H, and the O-ring 43 provides a liquid-tight seal between the second stator core 40 (fitting portion 40C) and the valve case 19 of the damping force adjusting valve 18. is sealed in

The non-magnetic ring 44 is a non-magnetic member positioned between the first and second stator cores 36 and 40 and provided on the inner peripheral side of the molded coil 34 (coil 34A). The non-magnetic ring 44 is formed as a stepped cylindrical body made of a non-magnetic material such as austenitic stainless steel. The nonmagnetic ring 44 is composed of a thick cylindrical portion 44A in the middle in the axial direction and first and second fitting cylindrical portions 44B and 44C projecting axially from both ends of the thick cylindrical portion 44A. there is

Here, in the nonmagnetic ring 44, the thick cylindrical portion 44A and the fitting cylindrical portions 44B and 44C have the same outer diameter. However, as shown in FIG. 4, the thick tubular portion 44A is formed to have the smallest inner diameter dimension D1, and the first and second fitting tubular portions 44B and 44C have the thick tubular portion 44A (dimension D1). It is formed with a larger inner diameter than the The first and second fitting cylinder portions 44B and 44C are formed of a non-magnetic material with a required thickness (thickness in the radial direction) so as to ensure desired coaxiality with the thick-walled cylinder portion 44A. .

The first fitting tubular portion 44B of the non-magnetic ring 44 is fitted onto the small-diameter tubular portion 36A of the first stator core 36 from the outside, and the two are joined together by a brazing portion 45 . The second fitting tubular portion 44C is fitted to the outer peripheral sides of the tubular portion 40A and the conical protrusion 40E of the second stator core 40, and the two are joined by the brazing portion 46. As shown in FIG. The brazing portions 45 and 46 are made of brazing material made of pure copper brazing material and subjected to, for example, a brazing treatment of 1000° C. or more (a pure copper brazing solution treatment) so that the non-magnetic ring 44 becomes the first and second brazing material. are joined to the stator cores 36, 40 of the . A rapid cooling process is performed after the brazing process.

The brazing portions 45 and 46 join the non-magnetic ring 44 to the first and second stator cores 36 and 40 with a thickness of about 25 to 51 μm, for example. In this state, the inner diameter of the non-magnetic ring 44 (that is, the dimension D1 of the thick cylindrical portion 44A) is larger than the inner diameter of the first stator core 36, as shown in FIG. , the radial dimension of the concave portion 40D). The inner diameter of the non-magnetic ring 44 (that is, the dimension D1 of the thick cylindrical portion 44A) is larger than the inner diameters of the first and second stationary cores (first and second stator cores 36, 40). . In this embodiment, the inner diameter of the non-magnetic ring 44 is larger than the inner diameters of the first and second fixed cores. The diameter may be smaller than the inner diameter of the fixed core. Making the inner diameter of the non-magnetic ring 44 smaller or larger than the inner diameters of the first and second stationary cores means that the non-magnetic ring 44 can be used as the inner diameter of the first and second stationary cores. It means that the inside is not cut after brazing (if not cut, the inner diameters of the non-magnetic ring 44 and the first and second fixed iron cores have tolerances, and the inner diameters of mass-produced products are all the same. cannot be).

An annular gap 47 is formed between the small-diameter tubular portion 36A of the first stator core 36 and the first fitting tubular portion 44B of the non-magnetic ring 44 on the outer peripheral side thereof. This gap 47 is for pouring the brazing material (pure copper brazing material) in a heat-melted state between the first stator core 36 (small-diameter cylindrical portion 36A) and the non-magnetic ring 44 (first fitting cylindrical portion 44B). It is an introductory route. This gap 47 functions as a gap for absorbing the difference in thermal expansion between the first and second stator cores 36 and 40 and the non-magnetic ring 44 .

The brazing material of the brazing portion 46 is also provided between the second stator core 40 (the outer peripheral surfaces of the tubular portion 40A and the conical protrusion 40E) and the non-magnetic ring 44 (the second fitting tubular portion 44C). An introduction passage for pouring (pure copper solder) in a heated and melted state is formed in the same manner as the gap 47 . However, the non-magnetic ring 44 heats the brazing material (pure copper brazing material) in order to join the second fitting tubular portion 44C to the second stator core 40 (the tubular portion 40A and the outer peripheral side of the conical protrusion 40E). When poured in a molten state, an axial external force is applied between the two to eliminate the gap as much as possible. However, a difference in thermal expansion occurs between the first and second stator cores 36 and 40 and the non-magnetic ring 44 due to the difference in materials.

Therefore, an axial gap 47 is formed between the small-diameter tubular portion 36A of the first stator core 36 and the first fitting tubular portion 44B of the non-magnetic ring 44 so as to extend over the entire circumference. In this way, the non-magnetic ring 44 is joined between the first and second stator cores 36, 40 at the brazing portions 45, 46, and the rapid cooling process after brazing eliminates the difference in materials between them. Even if a difference in thermal expansion occurs due to the gap 47, the gap 47 can suppress the occurrence of distortion based on the difference. A non-magnetic ring 44 as a non-magnetic member is provided between the first and second stator cores 36 and 40 (stationary iron cores), and is integrated with the first and second stator cores 36 and 40 by brazing. fixed to

A plunger 48 as a movable iron core is arranged on the inner peripheral side of the first and second stator cores 36, 40 (first and second fixed iron cores) and the non-magnetic ring 44 (non-magnetic member), and moves in the axial direction. possible. That is, the plunger 48 is arranged on the inner peripheral side of the first and second stator cores 36 and 40 and the non-magnetic ring 44, and the first and second bushes 38 and 41 and the operating pin 49 are moved by the magnetic force generated in the coil 34A. It is provided movably in the axial direction via the . A plunger 48 is fixedly mounted on an actuation pin 49 extending through its central side and moves therewith. The operating pin 49 is axially slidably supported by the core lid 37 on the first stator core 36 side and the second stator core 40 via first and second bushes 38 and 41 .

Here, like the first and second stator cores 36 and 40, the plunger 48 is made of an iron-based magnetic material and has a substantially cylindrical shape. It generates a thrust in the direction of being sucked into the recess 40D. Further, the plunger 48 is formed with a plurality of communication passages 48A that are spaced apart in the circumferential direction and extend in the axial direction (forward and backward directions). These communication passages 48A allow the oil in the first and second stator cores 36 and 40 to smoothly flow through the communication passages 48A while the plunger 48 is axially displaced together with the operating pin 49. It is a flow passage for suppressing the occurrence of flow resistance to the plunger 48 .

The operating pin 49 is a shaft portion that transmits the thrust of the plunger 48 to the pilot valve body 32 of the damping force adjusting valve 18, and is formed of a hollow rod. A plunger 48 as a movable iron core is integrally fixed to the axially intermediate portion of the operating pin 49 by means of press fitting or the like, whereby the plunger 48 and the operating pin 49 are sub-assembled. Both sides of the operating pin 49 in the axial direction are slidable on the core lid body 37 on the first stator core 36 side and the second stator core 40 (cylindrical portion 40A) via first and second bushes 38 and 41. supported by

One end of the operating pin 49 (the left end in FIG. 2) protrudes from the second stator core 40, and the pilot valve body 32 of the damping force adjusting valve 18 is fixed to the protruding end. Therefore, the pilot valve body 32 moves together with the plunger 48 and the operating pin 49 in the axial direction. In other words, the valve opening set pressure of the pilot valve body 32 is a pressure value corresponding to the thrust force of the plunger 48 based on the energization of the coil 34A. The plunger 48 is configured to open and close the pilot valve of the hydraulic shock absorber 1 (that is, the pilot valve body 32 with respect to the pilot body 26) by moving in the axial direction by the magnetic force from the coil 34A.

The back pressure chamber 50 is an oil chamber formed between the core lid 37 and the other end of the operating pin 49 (the right end in FIG. 2). This back pressure chamber 50 communicates with the center hole 24B side of the pilot pin 24 via a hollow rod (actuating pin 49). Therefore, the same pressure as that of the pilot valve element 32 that is seated on and off the valve seat portion 26</b>E of the pilot body 26 acts on the back pressure chamber 50 . However, as for the pressure receiving area for this pressure, the area where the other end surface of the operating pin 49 in the back pressure chamber 50 receives pressure is larger than the area between the pilot valve body 32 (one end side of the operating pin 49) and the valve seat portion 26E. It is smaller than the pressure-receiving area.

As a result, the thrust to be transmitted from the plunger 48 to the pilot valve body 32 of the damping force adjusting valve 18 via the operating pin 49 can be reduced by the pressure receiving area difference between the two. That is, by forming the back pressure chamber 50 between the operating pin 49 and the core lid body 37 on the other end side of the operating pin 49 , the pressure is transmitted from the plunger 48 to the pilot valve body 32 of the damping force adjusting valve 18 via the operating pin 49 . The required thrust (for example, the magnetic force to be generated by the coil 34A of the molded coil 34) can be reduced, and the size and weight of the entire solenoid 33 can be reduced.

The cover member 51 is a magnetic cover that covers the outer periphery of the coil 34A. The cover member 51 is formed as a yoke using a magnetic material (magnetic body), and forms a magnetic circuit (magnetic path) on the outer peripheral side of the molded coil 34 (coil 34A). Here, the cover member 51 is formed in a cylindrical shape with a bottom as a whole, and includes a cylindrical cylindrical case 51A and the other end of the cylindrical case 51A (the right end in FIGS. 2 and 3). It is roughly composed of a closing plate 51B. A notch (not shown) for exposing the cable extraction portion of the molded coil 34 described above from the cover member 51 is provided in the tubular case 51A.

Here, the plate 51B of the cover member 51 is provided with a fitting recess 51C into which the core lid body 37 (its bottom side) of the first stator core 36 is fitted or accommodated. The first stator core 36 can exchange magnetic flux with the plate 51B of the cover member 51 by fitting the bottom side of the core lid 37 into the fitting recess 51C.

On the other hand, the inner peripheral surface of the cylindrical case 51A of the cover member 51 faces the outer peripheral surface of the molded coil 34 with a gap therebetween. This gap is configured to prevent the radial force applied to the cover member 51 from being directly applied to the molded coil 34 . Further, the outer peripheral surface of the annular portion 40B of the second stator core 40 is in contact with the inner peripheral surface of the cylindrical case 51A by, for example, light press-fitting. magnetic flux can be exchanged between

At the end of the cover member 51 on the opening side (that is, at one end in the axial direction of the cylindrical case 51A located on the left side in FIG. 2), there is an engagement convex portion that protrudes radially outward from other portions. 51D are provided (over the entire circumference or at a plurality of locations spaced apart in the circumferential direction). The engagement projection 51D is engaged with a coupling ring 52 that is screwed onto the valve case 19 of the damping force adjustment valve 18 .

The coupling ring 52 is formed in a substantially cylindrical shape, and has a female threaded portion 52A screwed to the male threaded portion 19B of the valve case 19 and an outer diameter size of the engaging convex portion 51D of the cylindrical case 51A. A brim-shaped engaging portion 52B extending radially inward is provided so as to be smaller than the diameter. The coupling ring 52 is formed by screwing the female threaded portion 52A and the male threaded portion 19B of the valve case 19 together with the flange-like engaging portion 52B in contact with the engaging convex portion 51D of the cylindrical case 51A. It is a connecting member that integrally connects the damping force adjusting valve 18 and the solenoid 33 .

The solenoid 33 and the hydraulic shock absorber 1 according to this embodiment have the constructions described above, and the operation thereof will be described below.

First, when mounting the hydraulic shock absorber 1 on a vehicle such as an automobile, for example, the projecting end (upper end) side of the piston rod 8 is attached to the vehicle body side, and the mounting eye 3A provided on the bottom cap 3 is attached to the wheel side. be done. The solenoid 33 of the damping force adjusting device 17 is connected to a control device (controller) provided on the vehicle body side of the vehicle via an electric wiring cable (both not shown) or the like.

When the vehicle is running, if vibrations occur in the vertical direction due to unevenness of the road surface, etc., the piston rod 8 is displaced so as to extend or contract from the outer cylinder 2, and a damping force is generated by the damping force adjusting device 17 or the like. can dampen vehicle vibrations. At this time, the controller variably controls the damping force generated by the hydraulic shock absorber 1 by changing the current value of the control signal that energizes the coil 34A of the solenoid 33 and adjusting the valve opening pressure of the pilot valve body 32. can do.

Here, the magnetic force (magnetic flux) generated by the coil 34A of the solenoid 33 passes from the first stator core 36 to the movable iron core (plunger 48) side so as to avoid the non-magnetic ring 44, which is a non-magnetic member. 2 of the stator core 40 (that is, the conical protrusion 40E, the tubular portion 40A, the annular portion 40B, and the fitting portion 40C), the tubular case 51A of the cover member 51, the plate 51B, and the first stator core. Configure the magnetic circuit to return to 36 .

The magnetic circuit in this case consists of the contact portion ( That is, the magnetic flux can be transferred by the portion where the magnetic bodies are in surface contact with each other. Therefore, the magnetic circuit of the solenoid 33 can ensure high magnetic efficiency.

By the way, between the first stator core 36 and the second stator core 40, which constitute the main part of the solenoid 33, a non-magnetic ring, which is a non-magnetic member, is positioned on the inner peripheral side of the molded coil 34 (coil 34A). 44 are provided. This non-magnetic ring 44 is brazed between the first and second stationary cores (first and second stator cores 36, 40) so as to increase the magnetic flux density of the magnetic circuit with respect to the movable core (plunger 48). They are joined by portions 45 and 46 . However, when the non-magnetic member (non-magnetic ring 44) is machined (for example, cutting the inner peripheral surface) after joining, the magnetic characteristics change due to machining strain at this time, and the non-magnetic member becomes magnetized. There is a problem that it becomes easy to be

Therefore, in the present embodiment, the non-magnetic ring 44 made of a non-magnetic material such as austenitic stainless steel, for example, is arranged in the axial direction from the thick cylindrical portion 44A in the middle of the axial direction and from both ends of the thick cylindrical portion 44A. The protruding first and second fitting cylinder portions 44B and 44C form a stepped cylindrical integral body. The nonmagnetic ring 44 has an inner diameter D1 larger than the inner diameters of the first and second stator cores 36 and 40 .

That is, the non-magnetic ring 44 is joined between the first stator core 36 and the second stator core 40 by the brazing portions 45 and 46, and the inner diameter of the non-magnetic ring 44 (that is, the thickness of the thick cylindrical portion 44A). Dimension D1) is formed to be larger than the inner diameter of the first stator core 36 and larger than the inner diameter of the second stator core 40 (that is, the radial dimension of the concave portion 40D), as shown in FIG. there is

For this reason, a plunger 48 as a movable core is axially mounted on the inner peripheral side of the first and second stator cores 36 and 40 (first and second fixed cores) and the non-magnetic ring 44 (non-magnetic member). It can be arranged movably. That is, since the plunger 48 can be arranged inside the non-magnetic ring 44 with a gap, the non-magnetic ring 44 is machined (for example, cut the inner peripheral surface) after joining the first and second stator cores 36 and 40. ), and the magnetic characteristics of the non-magnetic ring 44 do not change due to thermal effects, strain, or the like.

In this case, the non-magnetic ring 44 is a non-magnetic member made of austenitic stainless steel, and the non-magnetic ring 44 is joined between the first stator core 36 and the second stator core 40 by brazing portions 45 and 46. When doing so, brazing is performed using pure copper solder (brazing material) or the like. That is, austenitic stainless steel can be subjected to solution heat treatment at 1000° C. or higher, for example, to remove deformation-induced martensite and return the crystal structure to the ideal face-centered cubic structure as a non-magnetic material. can.

In general, when a non-magnetic austenitic stainless steel part is strained by deep drawing or machining, the material generates deformation-induced martensite, and some crystal structures are ideal for non-magnetic materials. It transforms into a body-centered cubic structure instead of a centered cubic structure, resulting in the property that the non-magnetic material is easily magnetized. However, deformation-induced martensite in austenitic stainless steel is removed by heat treatment at 1000° C. or higher, and the ideal face-centered cubic structure is restored. This treatment is called solution heat treatment.

Therefore, in the present embodiment, pure copper brazing material is selected as a brazing material having a brazing temperature of 1000° C. or higher, and the brazing portions 45 and 46 are subjected to a treatment that serves as both brazing and solution heat treatment. The crystal structure of the nonmagnetic ring 44 joined between the second stator cores 36 and 40 can be restored to the ideal face-centered cubic structure as a nonmagnetic material. Moreover, since the non-magnetic ring 44 is press-fitted between the first and second stator cores 36, 40 and butted against each other, thermal deformation due to high temperatures during brazing is suppressed, and the shape correction is performed after brazing. It is possible to maintain the desired dimensions and shape without the need for cutting. As long as the brazing material has a brazing temperature of 1000° C. or higher, it may be other than pure copper brazing material. For example, brass brazing, nickel brazing, gold brazing, palladium brazing, etc. may be used.

Thus, according to the present embodiment, it is possible to suppress changes in the characteristics of the non-magnetic ring 44 (non-magnetic member) due to thermal effects, distortion, etc. A high magnetic flux density can be maintained through the non-magnetic ring 44 (non-magnetic member). The magnetic circuit of the solenoid 33 consists entirely of magnetic materials except for the transfer of magnetic flux between the plunger 48 and the first stator core 36 facing each other across a minute gap, and between the plunger 48 and the second stator core 40 as well. Since the magnetic flux can be exchanged while the surfaces are in contact with each other, the magnetic circuit of the solenoid 33 can ensure high magnetic efficiency.

Moreover, the first fitting cylinder portion 44B of the non-magnetic ring 44 is fitted to the small-diameter cylinder portion 36A of the first stator core 36 from the outside, and the two are joined together by the brazing portion 45 . The second fitting tubular portion 44C is fitted to the outer peripheral sides of the tubular portion 40A and the conical protrusion 40E of the second stator core 40, and both are joined by the brazing portion 46. As shown in FIG. The brazing portions 45 and 46 are made of brazing material made of pure copper brazing material, and are subjected to a brazing process at, for example, 1000° C. or higher, so that the non-magnetic ring 44 is attached to the first and second stator cores 36 and 40. After joining and brazing, a rapid cooling process is performed.

Thus, in this embodiment, the first and second stator cores 36 and 40 and the non-magnetic ring 44 are configured as described above, and the brazing portions 45 and 46 are made of pure copper brazing (brazing material). For example, by performing a brazing process at 1000° C. or higher, the three members of the first and second stator cores 36 and 40 and the non-magnetic ring 44 can be joined together in a shape that satisfies coaxiality. Pressure resistance against pressure oil can also be ensured.

Therefore, the solenoid 33 employed in the present embodiment is used in a semi-ac (damping force adjustable shock absorber) to adjust the opening/closing operation of the damping force adjustment valve 18. As a means for providing a non-magnetic portion for the purpose of forming a magnetic path between the stator cores 36, 40) and the movable core (plunger 48), magnetic members (first and second stator cores 36, 40) Joining the non-magnetic member (non-magnetic ring 44) with the brazing portions 45, 46 can provide an optimum method for enabling the damping force adjustment valve 18 to withstand a high pressure resistance.

That is, by setting the brazing temperature at which the non-magnetic ring 44 is joined between the first and second stator cores 36 and 40 to 1000° C. or more as described above, the solution heat treatment also serves as It is possible to remove deformation-induced martensite (body-centered cubic structure), and obtain a metal structure with an ideal face-centered cubic structure as a magnetic property. And since no machining is performed for the purpose of correcting the shape after brazing, the ideal metal structure as a non-magnetic material is maintained without causing work-induced martensite, and thermal deformation during brazing is prevented. It can be a structure that suppresses it.

As a result, the non-magnetic ring 44 as the non-magnetic portion has an ideal metal structure, excellent magnetic characteristics can be obtained, and the thrust of the solenoid 33 can be improved and the thrust waveform can be optimized. In addition, the number of steps in manufacturing the solenoid 33 is reduced, and workability and productivity can be improved.

In the above-described embodiment, the second stator core 40 is configured to include the cylindrical cylindrical portion 40A, the annular portion 40B, and the cylindrical fitting portion 40C projecting to one side in the axial direction. mentioned and explained. However, the present invention is not limited to this. It is also possible to adopt a configuration in which the shaped fitting portion is omitted or abolished.

Further, in the above embodiment, the case where the cover member 51 is made of a magnetic material as a yoke has been described as an example. However, the present invention is not limited to this. For example, the cover member may be made of a non-magnetic material, and an open coil solenoid without a yoke may be used. Furthermore, in the above embodiment, the case where the solenoid 33 is configured as a proportional solenoid has been described as an example. However, it is not limited to this, and may be configured as an ON/OFF type solenoid, for example.

Next, the inventions included in the above embodiments will be described. That is, as a first aspect of the present invention, there are provided a cylinder in which a working fluid is sealed, a piston inserted into the cylinder and defining the inside of the cylinder into a rod-side chamber and a bottom-side chamber, and a piston connected to the piston. a piston rod extending to the outside of the cylinder; a flow path in which the working fluid flows due to the movement of the piston rod; and a damping force adjustment valve provided in the flow path whose opening/closing operation is adjusted by a solenoid. The solenoid includes a coil that generates magnetic force when energized, first and second fixed iron cores provided on the inner peripheral side of the coil, and the first and second a non-magnetic member provided between the fixed cores and integrally fixed to the first and second fixed cores by brazing; and the first and second fixed cores and the non-magnetic member a movable iron core disposed on an inner peripheral side and provided movably in an axial direction; a shaft portion provided on the movable iron core; and first and second bushings supporting the shaft portion, wherein the shaft portion is provided with the valve body of the damping force adjusting valve at the end on the side of the second fixed core, and the inner diameter of the non-magnetic member is larger than the inner diameters of the first and second fixed cores. It is characterized by its diameter or small diameter.

A damping force adjustable shock absorber according to a second aspect of the present invention is, in the first aspect, wherein the non-magnetic member is a member made of austenitic stainless steel. Further, in the damping force adjustable shock absorber according to the third aspect of the present invention, in the first or second aspect, the non-magnetic member is a brazing material having a brazing temperature of 1000 degrees or higher. attached. A damping force adjustable shock absorber according to a fourth aspect of the present invention is the third aspect, wherein the non-magnetic member is brazed using a brazing material made of pure copper brazing.

A solenoid according to a fifth aspect of the present invention includes a coil that generates magnetic force when energized, first and second fixed iron cores provided on the inner peripheral side of the coil, and a magnetic field between the first and second fixed iron cores. and a non-magnetic member integrally fixed to the first and second fixed cores by brazing; a movable iron core provided movably in an axial direction; a shaft portion provided on the movable iron core; and first and second bushings supporting the shaft portion; The inner diameter of the nonmagnetic member is characterized by being larger or smaller than the inner diameter of the iron core.

A sixth aspect of the present invention is a solenoid according to the fifth aspect, wherein the non-magnetic member is a member made of austenitic stainless steel. A solenoid according to a seventh aspect of the present invention is the fifth or sixth aspect, wherein the non-magnetic member is brazed using a brazing material having a brazing temperature of 1000° C. or higher. In the solenoid according to an eighth aspect of the present invention, in the seventh aspect, the non-magnetic member is brazed using a brazing material made of pure copper brazing. A solenoid according to a ninth aspect of the present invention is a solenoid according to any one of the fifth to eighth aspects, wherein an inner diameter portion defining an inner diameter of the first and second fixed cores and an inner diameter of the non-magnetic member are defined. The inner diameter portion is characterized in that it is not machined after brazing.

A tenth aspect of the present invention is a cylinder in which a working fluid is enclosed, a piston inserted into the cylinder and defining the inside of the cylinder into a rod side chamber and a bottom side chamber, and a piston connected to the piston and the cylinder a piston rod extending to the outside of the damping device, a flow path through which the working fluid flows due to the movement of the piston rod, and a damping force adjustment valve provided in the flow path whose opening and closing operation is adjusted by a solenoid. In a force-adjustable shock absorber, the solenoid includes a coil that generates magnetic force when energized, first and second fixed iron cores provided on the inner peripheral side of the coil, and the first and second fixed iron cores. A non-magnetic member provided between and integrally fixed to the first and second fixed cores by brazing, and inner peripheral sides of the first and second fixed cores and the non-magnetic member a movable iron core provided movably in the axial direction; a shaft portion provided on the inner peripheral side of the movable iron core; and first and second bushings supporting the shaft portion; The valve element of the damping force adjusting valve is provided at the end of the portion on the side of the second fixed core, and the inner diameter portion defining the inner diameter of the non-magnetic member is not subjected to machining after brazing. is characterized by

In addition, the present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Also, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is possible to add, delete, or replace part of the configuration of each embodiment with another configuration.

This application claims priority based on Japanese Patent Application No. 2018-241220 filed on December 25, 2018. The entire disclosure, including the specification, claims, drawings, and abstract of Japanese Patent Application No. 2018-241220 filed on December 25, 2018, is incorporated herein by reference.

1 Hydraulic Shock Absorber (Damping Force Adjustable Shock Absorber) 4 Inner Pipe (Cylinder) 5 Piston 8 Piston Rod 17 Damping Force Adjusting Device 18 Damping Force Adjusting Valve 32 Pilot Valve Element (Valve Element) 33 Solenoid 34 Molded Coil 34A Coil 36 Second 1 stator core (first fixed core) 37 core cover 38 first bush 40 second stator core (second fixed core) 40A tubular portion 41 second bush 44 nonmagnetic ring (nonmagnetic member) 45, 46 Brazed portion 48 Plunger (movable iron core) 49 Operating pin (shaft) A Reservoir chamber B Rod side oil chamber (rod side chamber) C Bottom side oil chamber (bottom side chamber) D Annular oil chamber (flow path) D1 Dimensions (non inner diameter of the magnetic member)

Claims (8)

A damping force adjustable shock absorber, the damping force adjustable shock absorber comprising:
a cylinder in which the working fluid is sealed;
a piston that is inserted into the cylinder and divides the inside of the cylinder into a rod-side chamber and a bottom-side chamber;
a piston rod connected to the piston and extending to the outside of the cylinder;
a flow path through which the working fluid flows due to movement of the piston rod;
a damping force adjustment valve provided in the flow path and whose opening/closing operation is adjusted by a solenoid;
with
The solenoid is
a coil that generates magnetic force when energized;
First and second fixed iron cores provided on the inner peripheral side of the coil;
a non-magnetic member provided between the first and second stationary cores and integrally fixed to the first and second stationary cores by brazing;
a movable core disposed on the inner peripheral side of the first and second fixed cores and the non-magnetic member and provided movably in the axial direction;
a shaft provided on the movable core;
First and second bushes supporting the shaft,
A valve body of the damping force adjustment valve is provided at the end of the shaft portion on the second fixed core side,
The inner diameter of the non-magnetic member is larger or smaller than the inner diameters of the first and second fixed cores,
The non-magnetic member is joined to the second fixed core using a brazing material having a brazing temperature of 1000° C. or higher between the non-magnetic member and the conical projection provided at the end of the second fixed core, A damping force adjustable shock absorber, wherein an axial end of a magnetic member and the second fixed core are in contact with each other. In the damping force adjustable shock absorber according to claim 1,
The damping force adjustable shock absorber, wherein the non-magnetic member is a member made of austenitic stainless steel. In the damping force adjustable shock absorber according to claim 1 or 2,
The non-magnetic member is a damping force adjustable shock absorber which is brazed with a brazing material made of pure copper brazing. a coil that generates magnetic force when energized;
First and second fixed iron cores provided on the inner peripheral side of the coil;
a non-magnetic member provided between the first and second stationary cores and integrally fixed to the first and second stationary cores by brazing;
a movable core disposed on the inner peripheral side of the first and second fixed cores and the non-magnetic member and provided movably in the axial direction;
a shaft provided on the movable core;
First and second bushes supporting the shaft,
The inner diameter of the non-magnetic member is larger or smaller than the inner diameters of the first and second fixed cores,
The non-magnetic member is joined to the second fixed core using a brazing material having a brazing temperature of 1000° C. or higher between the non-magnetic member and the conical projection provided at the end of the second fixed core, A solenoid, wherein an axial end of a magnetic member and the second fixed core are in contact with each other. In the solenoid according to claim 4,
The non-magnetic member is a solenoid member made of austenitic stainless steel. In the solenoid according to claim 4 or 5,
The non-magnetic member is a solenoid obtained by brazing with a brazing material made of pure copper brazing. In the solenoid according to any one of claims 4 to 6,
The solenoid, wherein the inner diameter portion defining the inner diameters of the first and second fixed cores and the inner diameter portion defining the inner diameter of the non-magnetic member are not cut after brazing. A damping force adjustable shock absorber, the damping force adjustable shock absorber comprising:
a cylinder in which the working fluid is sealed;
a piston that is inserted into the cylinder and divides the inside of the cylinder into a rod-side chamber and a bottom-side chamber;
a piston rod connected to the piston and extending to the outside of the cylinder;
a flow path through which the working fluid flows due to movement of the piston rod;
a damping force adjustment valve provided in the flow path and whose opening/closing operation is adjusted by a solenoid;
with
The solenoid is
a coil that generates magnetic force when energized;
first and second fixed iron cores provided on the inner peripheral side of the coil;
a non-magnetic member provided between the first and second stationary cores and integrally fixed to the first and second stationary cores by brazing;
a movable core disposed on the inner peripheral side of the first and second fixed cores and the non-magnetic member and provided movably in the axial direction;
a shaft provided on the inner peripheral side of the movable iron core;
First and second bushes supporting the shaft,
A valve body of the damping force adjustment valve is provided at the end of the shaft portion on the second fixed core side,
The non-magnetic member is joined to the second fixed core using a brazing material having a brazing temperature of 1000° C. or higher between the non-magnetic member and the conical projection provided at the end of the second fixed core, A damping force adjustable shock absorber, wherein an axial end of a magnetic member and the second fixed core are in contact with each other.

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