JP3932446B2 - Power steering device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a hydraulic power steering apparatus used in a vehicle, and includes a check valve that prevents a backflow of hydraulic oil from a hydraulic actuator that generates a steering assist force to a hydraulic pump side. Relates to the device.
[0002]
[Prior art]
Conventionally, as this type of power steering apparatus, there is one disclosed in JP-A-11-49007. In this power steering apparatus, a check valve that prevents the pressure oil supplied to the hydraulic actuator from flowing back to the hydraulic pump side is provided in the input port of the hydraulic control valve, the output port of the hydraulic pump, or the hydraulic path. Built into the flare nut that is inserted into the pipe joint. The check valve has a casing constituted by an inner peripheral portion forming a flow path inside the flare nut, a movable stopper inserted into the casing, and the movable stopper so as to be in close contact with a valve seat formed in the casing. The coil spring is configured to be urged, and a C-type retaining ring that neglects the base end of the coil spring. This check valve prevents the so-called kickback phenomenon, in which the hydraulic oil supplied to the hydraulic actuator flows back to the hydraulic pump and takes the handle with external force applied to the wheels when the vehicle rides on the curb. Is done. In addition, since the check valve is built in the flare nut, the check valve is assembled at the same time as the flare nut is assembled. Therefore, productivity is improved compared to the case where these are assembled separately.
[0003]
[Problems to be solved by the invention]
By the way, in the said prior art, when the check valve closes, it does not consider about the collision sound which generate | occur | produces when a movable stopper (valve body) collides with a valve seat.
[0004]
When the check valve is opened, pressure oil (hydraulic oil) flows in from the inlet of the flare nut and flows through the gap between the outer peripheral portion of the movable stopper and the circumferential portion of the casing, and then the coil spring is Passes from the radially outer side to the inner side and flows out from the outlet of the flare nut. At this time, the coil spring is compressed in accordance with the amount of movement of the movable stopper, and the pressure oil is reduced in the radial direction by decreasing the pitch and reducing the radial flow area as the check valve opening increases. Will pass through. Therefore, the pressure loss of the pressure oil due to the decrease in the flow area in the radial direction of the coil spring increases as the flow rate of the hydraulic oil increases and the check valve opening increases, and the pressure loss increases. As a factor that reduces the responsiveness of the hydraulic actuator, there is a difficulty in restricting the degree of freedom in designing the power steering apparatus.
[0005]
Further, since the flare nut used in the power steering apparatus is a component having a small-diameter flow path, a C-type retaining ring for locking one end of the coil spring to the flare nut is provided from the end of the flare nut. It is not easy to attach to the mounting groove formed at a distant position, and it has been desired to improve the assembly of the retaining ring.
[0006]
The present invention has been made in view of such circumstances, and the inventions according to claims 1 to 4 can reduce noise caused by a collision sound when the check valve closes. It aims at providing the power steering device which can suppress the pressure loss of the hydraulic fluid by the compression coil spring of the non-return valve in the valve opening state as much as possible. The invention described in claim 2 further aims to facilitate assembly of the spring receiver of the check valve, and the invention described in claim 3 further facilitates the movement of the valve body of the check valve. An object of the present invention is to form a passage for suppressing pressure loss of hydraulic oil with a simple structure by using the guide piece, and the invention according to claim 4 further includes a spring receiver fixed to the valve body. It is an object of the present invention to suppress hydraulic oil pressure loss due to a compression coil spring.
[0007]
[Means for Solving the Problems and Effects of the Invention]
  According to a first aspect of the present invention, there is provided a hydraulic pump having a discharge port forming portion in which a discharge port through which hydraulic oil is discharged is formed, a hydraulic actuator that is operated by hydraulic pressure of the hydraulic oil and generates a steering assist force, and the hydraulic pressure A hydraulic control valve provided between the pump and the hydraulic actuator for controlling supply / discharge of hydraulic oil to / from the hydraulic actuator, and a hydraulic oil inlet port for receiving the hydraulic control valve and accommodating the hydraulic control valve are formed A valve housing having an inlet port forming portion, and a conduit through which the hydraulic oil circulates to components from the discharge port forming portion to the inlet port forming portion constituting the hydraulic oil supply system to the hydraulic actuator Therefore, a connecting member coupled to the component is used as a valve body to prevent backflow of hydraulic oil from the hydraulic actuator to the hydraulic pump side. In the power steering apparatus including the check valve, the check valve is disposed in an oil passage formed in the connection member, and at least a portion that contacts the valve seat is formed of a synthetic resin. And a compression coil spring that urges the valve body to be seated on the valve seat portion, and the check valve includes the check valve without hydraulic oil passing through the compression coil spring in the radial direction. A first passage that allows flow between the inlet portion and the outlet portion is formed radially outward of the compression coil spring and along the moving direction of the valve body.The valve body has a first holding portion for holding one end portion of the compression coil spring, and the first holding portion is located on a bottom portion with which the one end portion abuts and radially outward of the compression coil spring. The one end portion includes a cylindrical side portion extending in the axial direction of the compression coil spring from the bottom portion, and a central projecting portion extending in the axial direction from the bottom portion in the internal space of the compression coil spring. Forms a cylindrical groove into which is insertedThis is a power steering device.
[0008]
As a result, in the power steering apparatus having a check valve that prevents the occurrence of the kickback phenomenon, the portion of the check valve that contacts the valve seat portion of the valve body is made of synthetic resin, so the check valve is closed. When this occurs, the collision sound generated when the valve body collides with the valve seat is reduced as compared with the case where the contacting portion is metal. In addition, when the check valve is opened, the hydraulic oil flowing in from the inlet portion of the check valve is deflected radially outward by the valve body, and is not accompanied by a large deflection in the flow direction. It flows into the first passage formed radially outward, and the main flow reaches the outlet through the first passage without passing through the compressed compression coil spring in the radial direction.
[0009]
As a result, according to the first aspect of the present invention, the following effects can be obtained. That is, in a power steering apparatus having a check valve that prevents the occurrence of a kickback phenomenon, when the check valve closes, the collision sound that occurs when the valve body collides with the valve seat portion is reduced, Noise caused by the collision sound is reduced. Further, the check valve has a first passage that allows the hydraulic oil to flow between the inlet portion and the outlet portion without passing through the compression coil spring in the radial direction. When the check valve is opened, the hydraulic oil that has flowed in from the inlet portion of the check valve flows into the first passage without a large deflection in the flow direction. The main flow of hydraulic oil reaches the outlet through the first passage without passing through the compression coil spring in the radial direction. Since it reaches the outlet through the first passage without passing through the compression coil spring in the radial direction, the hydraulic oil pressure loss due to the compression coil spring of the check valve can be reduced as much as possible, and the response of the hydraulic actuator is improved. This increases the degree of freedom in designing the power steering device.
[0010]
  According to a second aspect of the present invention, in the power steering apparatus according to the first aspect, the compression coil bar is provided.Ne'sA spring receiver whose other end is fixed to the connecting member by caulking an end forming the outlet portion of the connecting member.2nd holding part formed inHeld inThe second holding part has a protruding part that protrudes in the axial direction and faces the central protruding part in the inner space and is not provided with an opening.Is.
[0011]
As a result, the spring receiver of the compression coil spring is fixed by caulking the end portion that forms the outlet portion of the check valve to the connecting member that is the valve body. As a result, according to the invention described in claim 2, in addition to the effect of the invention described in claim 1, the following effect is exhibited. That is, the spring receiver of the compression coil spring is fixed to the end portion that forms the outlet portion of the connecting member by caulking the end portion, so that the assembly of the spring receiver to the connecting member is facilitated. The assemblability of the check valve in which the spring receiver is fixed to the connecting member (valve body) is improved.
[0012]
  According to a third aspect of the present invention, in the power steering apparatus according to the first or second aspect, a plurality of guide pieces that are in contact with the wall surface of the oil passage are spaced in the circumferential direction on the outer peripheral surface of the valve body. The first passage is formed by the guide piece adjacent between the wall surface and the valve body in the circumferential direction.The central protruding portion extends longer in the axial direction than the downstream end portion of the side portion having the outer peripheral surface.Is.
[0013]
Thus, when the valve body moves, the valve body is guided by the plurality of guide pieces formed on the valve body slidingly contacting the wall surface, so that the valve body can be smoothly moved in the connecting member. And the 1st channel | path for suppressing the pressure loss of hydraulic fluid is formed using these guide pieces.
[0014]
As a result, according to the invention described in claim 3, in addition to the effect of the invention described in the cited claim, the following effect is produced. That is, when the check valve is opened and closed, the valve body is guided by a plurality of guide pieces that are in sliding contact with the wall surface, so that the movement of the valve body within the connecting member is smooth, and the guide pieces are used. Thus, the first passage can be formed with a simple structure.
[0015]
  According to a fourth aspect of the present invention, in the power steering apparatus according to the second aspect, a second passage is formed in the spring receiver at a position overlapping the first passage when viewed in the axial direction. On the other hand, near the center of the spring receiverSecondA holding part is formedThe protrusion is hemisphericalIs.
[0016]
As a result, the compression coil spring is held by the spring receiver fixed to the connecting member, and the main flow of the hydraulic oil flowing through the first passage passes through the second passage without passing through the compression coil spring in the radial direction. To reach.
[0017]
As a result, according to the invention described in claim 4, in addition to the effect of the invention described in claim 2, the following effect is exhibited. That is, the compression coil spring can be held by the spring receiver fixed to the connecting member, and the main flow of the hydraulic oil flowing through the first passage passes through the second passage without passing through the compression coil spring in the radial direction. Since the outlet portion is reached, even in the check valve in which the spring receiver is fixed to the connecting member, the pressure loss due to the hydraulic oil passing through the compression coil spring in the radial direction can be reduced as much as possible.
[0018]
In this specification, “axial direction”, “radial direction”, and “circumferential direction” mean “axial direction”, “radial direction”, and “circumferential direction” with respect to the compression coil spring, respectively.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to FIGS.
1 to 6 show a first embodiment of the present invention. 1 and 2, a power steering apparatus 1 to which the present invention is applied is a rack and pinion type hydraulic power steering apparatus mounted on a vehicle. The power steering apparatus 1 includes a reservoir 2 for storing hydraulic oil, a hydraulic pump 3, a gear box 10, a suction pipe 4 provided between the reservoir 2 and the hydraulic pump 3, a hydraulic pump 3 and a gear box 10. Between the gear box 10 and the reservoir 2, and a reflux pipe 6 provided between the gear box 10 and the reservoir 2.
[0020]
The hydraulic pump 3 driven by the internal combustion engine mounted on the vehicle connects the hydraulic oil that has been sucked from the reservoir 2 through the suction pipe 4 to a high pressure and is connected to a discharge port forming portion 3a in which a discharge port is formed. Is supplied to a power cylinder mechanism 16 (described later) provided in the gear box 10 through the supply pipe 5. The hydraulic oil discharged from the power cylinder mechanism 16 flows into the reservoir 2 through the reflux pipe 6.
[0021]
As shown in FIG. 1, the gear box 10 includes a cylindrical housing 12 that accommodates a rack shaft 11 movably in an axial direction thereof (in this embodiment, the left-right direction of the vehicle); And a valve housing 14 which is integrally formed near the end of the housing 12 and accommodates the hydraulic control valve 13. One end of a pair of tie rods 15 is connected to both ends of the rack shaft 11 via a pair of ball joints, and the other end of both tie rods 15 is connected to a steered wheel via an interlocking mechanism (not shown). Connected.
[0022]
A power cylinder mechanism 16 as a hydraulic actuator is provided in the middle portion of the housing 12. The power cylinder mechanism 16 includes a power cylinder 17 constituted by a part of the housing 12, a power piston 18 fixed to the rack shaft 11 and slidably fitted in the power cylinder 17 in the axial direction of the rack shaft 11. The first and second oil chambers 19 and 20 are a pair of working chambers formed on both sides of the power piston 18, respectively.
[0023]
The valve housing 14 has an input shaft 21 connected to a steering wheel (not shown) and an output shaft (not shown) connected so as to be relatively rotatable via a torsion bar 22 coupled to the input shaft 21 integrally. ) Are accommodated rotatably. A pinion that meshes with rack teeth formed on the rack shaft 11 is formed in the housing 12 at the lower end of the output shaft.
[0024]
As shown in FIG. 2, a hydraulic control valve 13 comprising a rotary valve has a valve shaft 23 that rotates integrally with an input shaft 21, and a valve sleeve 24 that houses the valve shaft 23 and rotates integrally with the output shaft. The hydraulic oil is supplied to and discharged from the first and second oil chambers 19 and 20 by relative rotation of a valve shaft 23 having a plurality of lands 23a and a valve sleeve 24 having a control groove 24a. The valve housing 14 is connected to the inlet port forming portion 14a in which the supply pipe 5 is connected and the inlet port 25 into which the hydraulic oil from the hydraulic pump 3 flows, and the first and second oil chambers 19 and 20. Connection portions 14b and 14c to which the first and second oil pipes 7 and 8 communicating with each other are connected, respectively, and a connection portion 14d to which the reflux pipe 6 is connected are provided.
[0025]
When the steering wheel is operated, the rack shaft 11 is moved in the axial direction by the pinion that meshes with the rack teeth, and the left and right steered wheels are steered via a pair of tie rods 15. At this time, the hydraulic control valve 13 is operated in response to the torsion amount of the torsion bar 22 due to the rotational difference between the input shaft 21 and the output shaft generated based on the reaction force from the road surface due to road resistance or the like, that is, the steering torque, The hydraulic oil from the hydraulic pump 3 is supplied to the first oil chamber 19 (or the second oil chamber 20) through the supply pipe 5 and the oil pipes 7 and 8 according to the operation direction of the steering wheel, while the second oil chamber The hydraulic oil in 20 (or the first oil chamber 19) is discharged to the reservoir 2 through the reflux pipe 6, and hydraulic pressure corresponding to the steering torque is generated in the first and second oil chambers 19 and 20 of the power cylinder mechanism 16, and both A steering assist force generated based on the differential pressure between the oil chambers 19 and 20 is added to the rack shaft 11 to reduce the driver's steering force.
[0026]
Therefore, the discharge port forming portion 3a, the inlet port forming portion 14a, and the supply pipe 5 between the two port forming portions 3a and 14a are used for supplying the hydraulic oil discharged from the hydraulic pump 3 to the power cylinder mechanism 16. , A component constituting a hydraulic oil supply system.
[0027]
By the way, referring to FIG. 3, the flare sheet 26 is inserted into the inlet port 25 of the inlet port forming portion 14a of the valve housing 14 that accommodates the hydraulic control valve 13, and the expanded distal end portion of the supply pipe 5 is the flare sheet. The flare sheet 26 is connected to the inlet port forming portion 14a and the supply pipe 5 is connected to the flare sheet 26 by being sandwiched between the flare nut 27 screwed into the inlet port forming portion 14a. Therefore, the flare sheet 26 constitutes a connection member for connecting the supply pipe 5 to the inlet port forming portion 14 a of the valve housing 14.
[0028]
  The inlet port forming portion 14a has a flare sheet 26 in which an oil passage 28 communicating with the supply pipe 5 is formed as a valve body, and is discharged from the hydraulic pump 3 and flows into the inlet port 25 through the supply pipe 5. Is opened when the hydraulic pressure exceeds a predetermined hydraulic pressure, and hydraulic oil is allowed to be supplied to the first and second oil chambers 19 and 20 of the power cylinder mechanism 16 via the hydraulic control valve 13, and In order to prevent the above-mentioned kickback phenomenon, the hydraulic oil in the first oil chamber 19 or the second oil chamber 20 flows backward to the hydraulic pump 3 side by an external force applied to the steered wheels when the vehicle rides on the curb. Built-in check valve 30 to preventBe.
[0029]
The check valve 30 is entirely made of a synthetic resin valve body 31, a compression coil spring 32 for seating the valve body 31 on a valve seat portion 26a formed on the flare seat 26, and a valve closing state, One end portion 32a has a spring receiver 33 that holds the other end portion 32b of the compression coil spring 32 held by the valve body 31, and the valve body 31, the compression coil spring 32, and the spring receiver 33 are arranged along the axis L1 of the compression coil spring 32. The flare sheet 26 is built in a state of being arranged side by side.
[0030]
  When the check valve 30 is opened and closed, the valve element 31 that moves in the direction parallel to the axial direction is brought into contact with and separated from the valve seat portion 26a, so that the oil passage 28 is more upstream than the valve seat portion 26a. The control unit 31a that opens and closes the configured inlet 28a (also the inlet of the check valve 30) and the wall 31b of the oil passage 28 contact the wall 31b of the oil passage 28 so that the valve body 31 accommodated in the oil passage 28 is oiled. A cylinder that forms a cylindrical groove 34 centered on the axis of the valve body 31 that is coaxial or parallel to the axis L1 of the compression coil spring 32 and a guide portion that slidably guides to the flare sheet 26 along the path 28 Is formed of a cylindrical side portion 31b, a columnar central projecting portion 31c, and a bottom portion 31d, and holds one end portion 32a of a compression coil spring 32 that is inserted into the groove 34 and abuts against the bottom portion 31d.As the first holding partHolding part 35.
[0031]
4 and 6 together, the guide portion protrudes radially outward at an equal interval in the circumferential direction on the outer circumferential surface 31e of the side portion 31b which is also the outer circumferential surface of the valve body 31 and is axial. Three or more extending in the direction, in this embodiment, five plate-shaped guide pieces 31f are provided. Each guide piece 31f extends in the axial direction longer than the downstream end portion 31b1 of the side portion 31b, and the front end surface 31f1 in the axial direction is positioned on the same plane as the front end surface 31c1 of the central projecting portion 31c. . The outer surface 31f2 of each guide piece 31f is in surface contact with the wall surface 26b of the oil passage 28, and guides the valve body 31 so that the valve body 31 moves in parallel with the axial direction.
[0032]
When the check valve 30 is opened between the outer peripheral surface 31e of the valve body 31 having the guide piece 31f and the wall surface 26b and between the guide pieces 31f adjacent in the circumferential direction, the inlet portion 28a A passage 36 through which hydraulic fluid flows through an outlet portion 28b (also an outlet portion of the check valve 30) constituted by a portion downstream of the spring receiver 33 of the oil passage 28 is provided in the moving direction of the valve body 31. Along the end surface of the downstream end portion 31b1 of the valve body 31. Therefore, these passages 36 are located radially outward of the compression coil spring 32.
[0033]
  The disc-shaped spring receiver 33 is disposed in the vicinity of the end surface of the end portion that forms the outlet portion 28b of the flare sheet 26, and is a thin annular protrusion 31g (see FIG. 3) formed at the end portion of the flare sheet 26. ), And is fixed to the flare sheet 26 by a caulking portion 38 formed by caulking the entire circumference. As shown in FIG. 5, the spring receiver 33 is in contact with the annularly closed outer ring portion 33 a that is caulked to the flare sheet 26 and the other end portion 32 b of the compression coil spring 32 that is positioned at the center of the spring receiver 33.As the second holding partThe holding portion 33b, the outer ring portion 33a, and the holding portion 33b are connected to each other to extend in the radial direction. In this embodiment, the three connecting portions 33c and the connecting portion 33c are spaced apart in the circumferential direction. A plurality of, in this embodiment, three arc-shaped long holes 37 are provided.
[0034]
  The holding portion 33b has a hemispherical protruding portion 33b1 protruding in the axial direction in the inner space of the compression coil spring 32, and the other end portion 32b of the compression coil spring 32 is engaged around the protruding portion 33b1, The radial movement of the compression coil spring 32 is prevented. Further, the protruding portion 33b1 is opposed to the central protruding portion 31c in the axial direction, and when the check valve 30 is opened, the distal end surface 31c1 of the central protruding portion 31c comes into contact with the protruding portion 33b1, so that the valve body 31 The valve body 31 occupies the maximum valve opening position at this time.Also, as shown in FIGS. 33b1 Is not provided with an opening.
[0035]
Further, as shown in FIG. 6, the passage 36 is formed so as to have a portion overlapping the passage 37 when viewed in the axial direction, so that the passage 36 has an inlet portion when the check valve 30 is opened. The main flow occupying most of the hydraulic oil flowing in from 28a is allowed to flow through the passage 36 in the axial direction and reach the outlet portion 28b without passing through the compression coil spring 32 in the radial direction. Further, an axial gap is formed between the downstream end portion 31b1 of the side portion 31b and the spring receiver 33 at the maximum opening position of the check valve 30. The gap can be adjusted to an optimum value by changing the protruding amount of the protruding portion 33b1 that defines the maximum valve opening position by plastically deforming the protruding portion 33b1.
[0036]
Next, operations and effects of the embodiment configured as described above will be described.
When the steering wheel is operated, the hydraulic oil discharged from the hydraulic pump 3 passes through the check valve 30 opened by the hydraulic pressure, and further operates according to the steering wheel operating direction and steering torque. 13 is supplied to the first oil chamber 19 (or the second oil chamber 20), while the hydraulic oil in the second oil chamber 20 (or the first oil chamber 19) passes through the hydraulic control valve 13 and the return pipe 6 The steering assist force is added to the rack shaft 11 through the reservoir 2.
[0037]
Then, when the vehicle rides on the curb, the external force applied to the steered wheels is transmitted to the rack shaft 11 so that the piston causes the hydraulic oil in the first oil chamber 19 or the second oil chamber 20 to flow backward to the hydraulic pump 3 side. In this case, the check valve 30 prevents the backflow, thereby preventing the kickback phenomenon.
[0038]
Here, the valve body 31 of the check valve 30 is formed of synthetic resin including the control unit 31a, and thus, when the check valve 30 closes, the valve body 31 collides with the valve seat portion 26a. The impact noise that occurs is reduced compared to the case where the portion of the valve body 31 that contacts the valve seat portion 26a is made of metal, noise caused by the collision noise is reduced, and the weight of the valve body 31 is reduced. In addition, the open / close response of the check valve 30 is improved.
[0039]
On the outer peripheral surface 31e of the valve body 31, a passage 36 that allows the working oil to flow between the inlet portion 28a and the outlet portion 28b of the check valve 30 is located radially outward of the compression coil spring 32 and the valve By extending to the downstream end 31b1 of the valve body 31 along the movement direction (axial direction) of the body 31, the check valve 30 passes through the supply pipe 5 when the check valve 30 is opened. The hydraulic oil flowing in from the inlet portion 28a flows radially outward along the control portion 31a, flows into the passage 36 without a large deflection in the flow direction, and the main flow of hydraulic oil is compressed coil spring. Since it reaches the outlet 28b of the check valve 30 through the passage 36 without passing through the radial direction 32, the pressure loss of the hydraulic oil due to the compression coil spring 32 of the check valve 30 can be reduced as much as possible. It becomes possible to improve the responsiveness of the power cylinder mechanism 16, and the degree of freedom in designing the power steering device 1 is large. Become.
[0040]
When the check valve 30 is opened and closed, the valve body 31 moves in the axial direction along the wall surface 26b by the sliding contact of the plurality of guide pieces 31f formed on the outer peripheral surface 31e with the wall surface 26b. Therefore, the movement of the valve element 31 in the flare seat 26 is smooth. And since the channel | path 36 is formed using these guide pieces 31f, the channel | path 36 can be formed with a simple structure.
[0041]
Since the spring receiver 33 of the compression coil spring 32 is fixed to the flare sheet 26, which is the valve body, by the caulking portion 38 at the end that forms the outlet portion 28b, the spring receiver 33 can be easily assembled to the flare sheet 26. Thus, the assemblability of the check valve 30 in which the spring receiver 33 is fixed to the flare seat 26 that is the valve body is improved.
[0042]
In the spring receiver 33, a passage 37 is formed at a position overlapping the passage 36 when viewed in the axial direction, and a holding portion that holds the other end 32b of the compression coil spring 32 near the center of the spring receiver 33 with respect to the passage 37. By forming 33b, the compression coil spring 32 can be held by the spring receiver 33 fixed to the flare sheet 26, and the main flow of the hydraulic oil flowing through the passage 36 passes through the compression coil spring 32 in the radial direction. The pressure loss due to the hydraulic oil passing through the compression coil spring 32 in the radial direction is reduced as much as possible even in the check valve 30 in which the spring receiver 33 is fixed to the flare seat 26. can do.
[0043]
Further, since the other end portion 32b of the compression coil spring 32 is held by the holding portion 33b so as to be prevented from moving in the radial direction, this is in contrast to the fact that the one end portion 32a is held by the holding portion 35 that forms the groove 34. As a result, buckling and tilting of the compression coil spring 32 can be effectively prevented.
[0044]
Further, the maximum opening position of the check valve 30 can be easily adjusted by changing the protruding amount of the protruding portion 31b1 that also serves as the holding portion 33b of the spring receiver 33 by plastic deformation.
[0045]
Next, a second embodiment of the present invention will be described with reference to FIGS. The second embodiment is different from the first embodiment mainly in the structure of the valve body of the check valve, and the rest has basically the same configuration. Therefore, description of the same part is omitted or simplified, and different points will be mainly described. In addition, the same code | symbol was used about the member same as the member of 1st Example, or a corresponding member.
[0046]
In the second embodiment, a pipe joint 41 made of a 90 ° elbow pipe constituting the valve body of the check valve 40 includes a connection part 41a into which the flare sheet 26 is inserted, and an inlet port forming part 14a of the valve housing 14. A screw formed in the inlet port forming portion 14a by being inserted into the insertion hole 44 formed in the flange portion 41e as shown in FIG. The valve housing 14 is coupled by a pair of bolts (not shown) that are screwed into the holes.
[0047]
The oil passage 42 formed in the pipe joint 41 includes a first oil passage 42a mainly formed in the connection portion 41a, and a second oil passage 42b mainly formed in the fitting portion 41b and orthogonal to the first oil passage 42a. As in the first embodiment, the supply pipe 5 is connected to the pipe joint 41 by being sandwiched between a flare sheet 26 and a flare nut 27 screwed into the connection part 41a. Therefore, the pipe joint 41 is a connecting member.
[0048]
In the pipe joint 41, the fitting body 41b includes the valve body 31, the compression coil spring 32, and the spring receiver 33 of the first embodiment, except for the size of the valve body 31, the compression coil spring 32, and the compression coil spring. 32 and a spring receiver 33 are incorporated.
[0049]
And the inlet part 42c of the non-return valve 40 is comprised in the upstream part rather than the valve seat part 41c formed in the pipe joint 41 among the 1st oil path 42a and the 2nd oil path 42b, and the check valve The outlet portion 42d of 40 is constituted by a portion on the downstream side of the spring receiver 33 in the second oil passage 42b.
[0050]
The valve body 31 is urged by the compression coil spring 32 so as to be seated on the valve seat portion 41c, and the guide piece 31f is a wall surface of the second oil passage 42b in which the valve body 31 is accommodated in the wall surface 41d of the oil passage 42. The valve body 31 is guided so that the valve body 31 moves in parallel with the axial direction by making surface contact with 41d1. Further, the spring receiver 33 is a protrusion 41g formed in the same manner as in the first embodiment on the end surface of the end portion where the outlet portion 42d of the oil passage 42 is formed (indicated by a two-dot chain line in FIG. 7). It is fixed to the pipe joint 41 by a caulking portion 43.
[0051]
According to the second embodiment, by replacing the flare sheet 26 with the pipe joint 41, the same operations and effects as the first embodiment can be achieved, and the following operations and effects can be achieved. That is, since the pipe joint 41 coupled to the valve housing 14 also constitutes the check valve 40, the assemblability of the valve body 31 and the compression coil spring 32 can be improved by using the pipe joint 41 larger than the flare seat 26. This improves the assembly of the power steering apparatus 1 having the check valve 40 that prevents the kickback phenomenon.
[0052]
Next, a third embodiment of the present invention will be described with reference to FIG. The third embodiment is different from the second embodiment mainly in the connection structure of the supply pipe 5, and the rest has basically the same configuration. Therefore, description of the same part is omitted or simplified, and different points will be mainly described. In addition, the same code | symbol was used about the member same as the member of 2nd Example, or a corresponding member.
[0053]
In the third embodiment, the supply pipe 5 is fixed to the connection part 41 a of the pipe joint 41 by being welded by the welding part 43. According to the third embodiment, the same operation and effect as in the second embodiment can be obtained, and the flare nut 27 is not used, so that the number of parts can be reduced.
[0054]
Next, a fourth embodiment of the present invention will be described with reference to FIG. The fourth embodiment is mainly different from the first embodiment in that there is no structure of the valve body of the check valve and no spring receiver fixed to the valve body, and the rest is basically the same in configuration. is there. Therefore, description of the same part is omitted or simplified, and different points will be mainly described. In addition, the same code | symbol was used about the member same as the member of 1st Example, or a corresponding member.
[0055]
The pipe joint 51 constituting the valve body of the check valve 50 is coupled to the inlet port forming portion 14a of the valve housing 14 by a bolt (not shown) as in the second embodiment. Similarly to the first embodiment, the supply pipe 5 is sandwiched and connected to the pipe joint 51 by a flare sheet 26 and a flare nut 27 screwed into the pipe joint 51, and the flare sheet 26 is inserted into the first pipe. An oil passage 52 including an oil passage 52a and a second oil passage 52b orthogonal to the first oil passage 52a is formed. Therefore, the pipe joint 51 is a connecting member.
[0056]
The pipe joint 51 incorporates the valve body 31 of the check valve 50 and the compression coil spring 32. Here, the valve body 31 is urged by the compression coil spring 32 so as to be seated on the valve seat portion 26a formed on the flare seat 26.
[0057]
The other end portion 32b of the compression coil spring 32 is formed on the wall surface 51a of the oil passage 52 of the pipe joint 51 so as to form an annular groove 53 in the wall surface 51a1 facing the valve body 31 in the axial direction. It is held by a holding portion 54 that includes a portion 51b, a peripheral portion 51c radially outward of the groove 53, and a bottom portion 51d. That is, the other end 32b of the compression coil spring 32 inserted into the groove 53 is held in contact with the bottom 51d. In order to assemble the check valve 50, the compression coil spring 32 is held by the holding portion 35 of the valve body 31, and the valve body 31 integrated with the compression coil spring 32 is assembled to the pipe joint 51. The flare sheet 26 is press-fitted so as to generate a fixing force that does not move the flare sheet 26 due to the spring force of the compression coil spring 32 when the valve 50 is in the closed state.
[0058]
The guide piece 31f is in surface contact with the wall surface 51a2 of the first oil passage 52a in which the valve body 31 is accommodated, and guides the valve body 31 so that the valve body 31 moves in parallel with the axial direction. Further, the valve element 31 occupies the maximum valve opening position by the front end surface 31c1 of the central projecting portion 31c coming into contact with the central portion 51b. At the maximum valve opening position, the front end surface 31b1 of the side portion 31b and the holding portion 54 A gap in the axial direction is formed between the formed wall surface 51a1 and the pressure loss as much as possible, and when the check valve 50 is opened, through this gap, the oil passage 52 is more than the valve seat portion 26a. The hydraulic oil that has flowed in from the inlet portion 52c configured by the upstream portion reaches the outlet portion configured by the second oil passage 52b, and further flows into the inlet port 25 of the valve housing 14.
[0059]
According to the fourth embodiment, except for matters relating to the spring receiver 33, the same operations and effects as the first embodiment are exhibited, and the following operations and effects are also achieved. That is, since the pipe joint 51 coupled to the valve housing 14 also constitutes the check valve 50, by using the pipe joint 51 larger than the flare seat 26, the assemblability of the valve body 31 and the compression coil spring 32 is improved. This improves the assembly of the power steering apparatus 1 having the check valve 50 that prevents the kickback phenomenon. Further, since the spring receiver 33 is not used, the number of parts is reduced.
[0060]
Hereinafter, an example in which a part of the configuration of the above-described embodiment is changed will be described with respect to the changed configuration.
In each of the above-described embodiments, the valve body 31 is entirely formed of a synthetic resin. However, at least a portion of the control unit 31a that contacts the valve seat portion is formed of a synthetic resin. There may be. Further, the passage 36 is formed on the outer peripheral surface 31e of the valve body 31. However, the outer peripheral surface of the valve body 31 is constituted by a cylindrical surface, and a groove is formed on the wall surface of the oil passage that is in surface contact with the outer peripheral surface. Can also be formed.
[0061]
In each of the above embodiments, the valve body constituting the check valve is the flare sheet 26 or the pipe joints 41 and 51 coupled to the inlet port forming portion 14a as a component, but the flare sheet is a connecting member. In addition to the valve housing 14, the 26 or the pipe joints 41 and 51 supply, for example, hydraulic fluid between the discharge port forming portion 3 a of the hydraulic pump 3 or between the hydraulic pump 3 and the hydraulic control valve 13 of the valve housing 14. The component which comprises the said supply system of hydraulic fluid including the pipe joint which mutually connects the some conduit | pipe which comprises the pipe | tube 5 may be sufficient.
[Brief description of the drawings]
FIG. 1 is an overall schematic view of a power steering apparatus including a check valve according to a first embodiment of the present invention.
2 is an explanatory diagram centering on an oil passage of the power steering apparatus of FIG. 1; FIG.
FIG. 3 is an enlarged view of a main part of FIG. 2;
4 is a side view of the valve body of the check valve of FIG. 1. FIG.
FIG. 5 is a view taken along the arrow A in FIG. 3 of the spring receiver of the check valve.
6 is a cross-sectional view of the flare nut that is a part of the check valve, taken along the line VI-VI in FIG.
7 shows a second embodiment of the present invention and corresponds to FIG. 3 of the first embodiment.
8 is a view taken in the direction of arrow B in FIG.
9 shows a third embodiment of the present invention and corresponds to FIG. 3 of the first embodiment.
FIG. 10 shows a fourth embodiment of the present invention and corresponds to FIG. 3 of the first embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Power steering device, 2 ... Reservoir, 3 ... Hydraulic pump, 3a ... Discharge port formation part, 4 ... Intake pipe, 5 ... Supply pipe, 6 ... Reflux pipe, 7, 8 ... Oil pipe,
10 ... Gearbox, 11 ... Rack shaft, 12 ... Housing, 13 ... Hydraulic control valve, 14 ... Valve housing, 14a ... Inlet port forming part, 15 ... Tie rod, 16 ... Power cylinder mechanism, 17 ... Power cylinder, 18 ... Power Piston, 19, 20 ... Oil chamber, 21 ... Input shaft, 22 ... Torsion bar, 23 ... Valve shaft, 24 ... Valve sleeve, 25 ... Inlet port, 26 ... Flare seat, 26a ... Valve seat, 27 ... Flare nut, 28 ... Oil passage, 28a ... Inlet part, 28b ... Outlet part,
30 ... Check valve, 31 ... Valve body, 31e ... Outer peripheral surface, 31f ... Guide piece, 32 ... Compression coil spring, 33 ... Spring receiver, 33b ... Holding part, 34 ... Groove, 35 ... Holding part, 36, 37 ... Passage , 38 ... Caulking part,
40 ... Check valve, 41 ... Pipe joint, 42 ... Oil passage, 42c ... Inlet part, 42d ... Outlet part, 43 ... Welded part, 44 ... Insertion hole,
50 ... Check valve, 51 ... Pipe joint, 52 ... Oil passage, 52c ... Inlet part, 52d ... Outlet part, 53 ... Groove, 54 ... Holding part,
L1 ... axis.

Claims (4)

A hydraulic pump having a discharge port forming portion in which a discharge port for discharging hydraulic oil is formed, a hydraulic actuator that is operated by hydraulic pressure of the hydraulic oil to generate a steering assist force, and between the hydraulic pump and the hydraulic actuator A hydraulic control valve for controlling supply / discharge of hydraulic oil to / from the hydraulic actuator, and an inlet port forming portion for accommodating the hydraulic control valve and forming an inlet port for hydraulic oil to the hydraulic control valve Coupled to the valve housing and a component through which hydraulic oil flows to the component from the discharge port forming part to the inlet port forming part constituting the hydraulic oil supply system to the hydraulic actuator. And a check valve for preventing a backflow of hydraulic oil from the hydraulic actuator to the hydraulic pump side. In Chikarakajito apparatus,
The check valve is disposed in an oil passage formed in the connecting member, and at least a portion that contacts the valve seat portion is formed of a synthetic resin, and the valve body is seated on the valve seat portion. A compression coil spring that urges the
The check valve has a first passage that allows hydraulic oil to flow between the inlet portion and the outlet portion of the check valve without passing through the compression coil spring in the radial direction. Formed in the direction outward and along the moving direction of the valve body,
The valve body has a first holding portion that holds one end portion of the compression coil spring, and the first holding portion is located on a radially outer side of the compression coil spring and a bottom portion with which the one end portion contacts. A cylindrical side portion extending in the axial direction of the compression coil spring from the bottom portion, and a central projecting portion extending in the axial direction from the bottom portion in the internal space of the compression coil spring, wherein the one end portion is formed. power steering apparatus characterized that you form a cylindrical groove to be inserted. The other end of the compression Koiruba value is held in the second holding portion formed in the spring receiving is fixed to the connecting member by caulking an end portion forming the outlet portion of the connecting member, said second holding unit, the power of claim 1, wherein Rukoto which having a protrusion opening is not provided with facing the central projecting portion in the inner space protruding in the axial direction Steering device. A plurality of guide pieces that contact the wall surface of the oil passage are formed on the outer peripheral surface of the valve body so as to protrude in the radial direction at intervals in the circumferential direction, and the first passage includes the wall surface and the valve body. and it is formed by the guide piece a circumferentially adjacent between said central protrusion, and features that you have elongated in the axial direction than the downstream end portion of the side having the outer circumferential surface The power steering apparatus according to claim 1 or 2. The spring receiver is formed with a second passage at a position overlapping the first passage when viewed in the axial direction, and the second holding portion is formed near the center of the spring receiver with respect to the second passage , projection power steering apparatus according to claim 2, wherein the hemispherical der Rukoto.

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