JPS606822B2 - Accumulated power steering device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The invention comprises a servo-pumped pressure accumulator, a control valve closed in a neutral position and operated by a steering shaft via a steering wheel, at least one servo motor with two pressure chambers; The present invention relates to an accumulator-operated dynamic two-power steering system, in particular for a motor vehicle, having a tank and associated lines.

For power steering systems, such as those operated by a pressure accumulator, in order to conduct the pressure medium into the pressure chamber of the servo motor, the control valve for power steering systems without a pressure accumulator has a 3 to A special control valve is required which must be shut off.

In the known pressure accumulator actuated power steering system, the operation is performed by a cylindrical control valve that is forcibly limited, but the pressure medium is cut off exclusively through the two circular pipes and valves at the neutral position of the control valve. It is done.

The control function is performed by one forcedly controlled cylindrical valve piston and two non-forced cylinder valves. The cylindrical valve piston has the advantage of being very simple and has high operational safety, and the valve has the advantage of high sealing performance, but it lacks forced control.
Also, since it is impossible to provide a chamfered portion, there is a drawback that the control function of the sushi disk and valve is inhibited. The object of the invention is to ensure that the flow of pressure medium is interrupted in the neutral position of the control valve, and that the regulation of the pressure medium flow is carried out completely by means of a force-controlled cylindrical control valve piston, and that To obtain a control valve device for a pressure accumulator actuated power steering device, in which a valve device of a simple structure consisting of a sleeve and a conical T-shaped valve piston is used as a valve for shutting off and circulating the flow of pressure medium. It is in.

This object of the invention is achieved by the features described in the patent claims.

Embodiments of the present invention will be described in detail below with reference to the drawings.

In the first control valve device, a control valve 2 and a circular valve 3 are arranged in a case 4.The control valve 2 is mounted in a valve sleeve 21 so as to be able to be displaced in the axial direction. It consists of a cylindrical valve piston 20 with two inflow pistons 22 and 23 and a return piston 1 within the valve sleeve 21.
24 are arranged. Valve piston 20', inflow groove 22
and 23 and two control grooves 25 and 26 which together with a reflux groove 24 form four control edges 27, 28, 29 and 30. The valve 3 is held on the valve seat 36 by a spring 371 supported by a spring seat 38' having two annular grooves 32 and 33 which are adjustable via screws 34 and are mounted in the case 4; It consists of a valve piston 36 with a shape. The inner diameter of the spring seat 38 is the same as the valve seat 3.
6, so the circular valve piston 35
is circular and forms an annular surface 39 which is constantly loaded by the cap pressure when the valve 3 is closed. The force required to push up the cone-shaped valve piston 35, that is,
The force required to overcome the pressing force synthesized from the area of the cross-shaped surface 39 x the pressure of the pressure accumulator and the force of the spring 37 is the force required to overcome the pressing force of the pin 90
The valve sleeve 21 is supported frictionally at the top and is kept proportional to the pressure in the accumulator.The valve sleeve 21 is provided with one damping perforation 40 and 41 in each case on the end side.The control valve arrangement 1
A connection 44 to the inlet line 101 is provided in the casing 4 to create a connection between the inflow line 101 and the rest of the pressure medium circulation system.
A connection 45 to the return line 11 and one connection 46 and 47 respectively to the lines 12 and 13 leading to the servo motor 7 are provided.

Note that the connecting portion 44 is connected to the ring-shaped miso 132, and the inflow passages 42 and 43 are connected to the ring-shaped groove 33 of the circular sushi valve 3. A servo pump is indicated at 5, which is connected to the pressure accumulator 6 and to the case 4 via a line 10. The servo motor 7 is divided by a servo piston 70 into two pressure chambers 71 and 72. Tank 8 is reflux pipe 11
The pressure medium circulation system is then closed. A steering shaft, not shown in FIG. 1, actuates the control valve 2 via its pin 90. The torsion bar 9 causes the control valve 2 to return via the pin 90. Serving for the actuation of the valve 3 is a support wedge 91 on the pin 90 for a ball 92 which thrusts the valve piston 35 through the bridge part 93 during the axial movement of the valve piston 20. The functions of the control valve device 1 will be explained below. In the neutral position of the control valve 2, the ring-shaped miso 132 of the valve 3 is loaded via the inlet line 10 by the pressure accumulator pressure. Sushi-shaped valve piston 3
5 is mounted on its valve seat 36 by means of an annular surface 39 loaded by a spring 37 on the one hand and by the accumulator pressure on the other hand.
Because it is held on top, the annular groove 32 remains separated from the annular groove 33. In order to prevent leakage oil losses between the inlet line 10 and the return line 11 as much as possible, the control edges 27 and 30 are additionally closed in the neutral position of the control valve 2. The annular groove 33, which communicates with the inlet grooves 122 and 23 via the inlet boreholes 42 and 43, therefore also remains separated from the return line 11, whereas the control valve 2 is placed in communication with the servo motor 7. Conduits 12 and 13 have open control edges 28 and 29
It is connected to reflux groove 24 through . If the pin 90 is then steered, for example, to shift the cylindrical valve piston 20 of the control valve 2 towards the right, the ball 92 will be pressed against the bridge member by the support wedge 91 and the valve The piston 35 is pushed up. As a result, the annular groove 32 is connected to the annular groove 33, so that the inflow grooves 22 and 2 of the control valve 2 are passed through the inflow passages 42 and 43.
3 is also loaded by the accumulator pressure. Thereafter, the rightward movement of the valve piston 20 first closes the control edge 29 and opens the control edge 30, so that the pressure chamber 72
is loaded by the accumulator pressure via line 13, and the servo piston 70 is moved to the left. In this case, the servo piston 70 displaces the pressure medium from the unloaded pressure chamber 71 via the line 12, the open control edge 28 and the return line 11 into the tank 8. In the second control valve device 101, a control valve 102 and two valves 103 and 203, which are coaxially arranged parallel to the control valve 102 and opposite to each other, are assembled in a case 104.

Control valve 102 consists of substantially the same parts as control valve 2. That is, it consists of a cylindrical valve piston 120 that is mounted in a valve sleeve 121 so as to be able to be shifted in the direction of the piston. There are two inlet grooves 122 in the valve sleeve 121.
and 123 and one reflux groove 124 are arranged. Valve piston 120 has inlet grooves 122 and 123.
as well as four control edges 127 along with a reflux groove 124
, 128, 129, and 130. The valves 103 and 203 are fitted with a valve sleeve 131 that is adjustably mounted within the case 104 via screws 134 or 234.
or 231. In addition, the valve 103 has two ring-shaped miso pastes 1132 and 133 on the valve sleeve 131.
as well as a spring seat 13 with a damping bore on its side.
It has a cone-shaped valve piston 135 held on a valve seat 136 by a spring 137 supported at 8. valve piston 1
35 is circular and has an annular surface 139 which is constantly loaded by the pressure plexer pressure when the valve 103 is closed. Yen sushi・
The valve 203 also has two annular rings 1232 and 233 on the valve sleeve 231 and a cone-shaped valve piston held in its valve seat 236 by a spring 237 supported on its side by a spring seat 238 with a damping bore. 2
It has 35. Valve piston 235 is circular and has an annular surface 239 that is constantly loaded by accumulator pressure when valve 203 is closed. A damping bore 140 and 141 is provided in each case on the end side in the valve sleeve 121 . An inlet line 1 is provided in the case 104 to create a connection between the control valve arrangement 101 and the other parts of the pressure medium circulation system.
10', a connection 145 to the return line 111 and one connection 1 in each case to the lines 112 and 113 leading to the servo motor 107.
46 and 147 are provided.

Note that the connecting portion 144 is connected to the annular grooves 132 and 232, and the inflow passages 142 and 143 are circular and the valve 10 is connected to the annular grooves 132 and 232.
3 and 203 are connected to ring-shaped miso 133 and 233. A servo pump is designated by 105, which is connected via a line 110 to the pressure accumulator 106 and to the case 104. The servo motor 107 has a servo piston 1701 and thus two pressure chambers 171 and 17.
Divided into 2. Tank 108 closes the pressure medium circulation system via return line 111. The steering shaft, which is not shown in FIG.
Activate 3. Torsion bar 109 causes control valve 102 to return via pin 190. The functions of the control valve device 101 described below are the same as in the control valve device 1.

In the neutral position of the control valve 102, the rings 1132 and 232 of the valves 103 and 203 are loaded with pressure accumulator pressure via the inlet line 110. On this occasion,
Due to the double separation of the inlet line 110 from the return line 111, firstly by the closed valves 103 and 203 and then by the closed control edges 127 and 130 of the control valve 102, the main In the invention, leakage oil loss is particularly low. At that time, for example, pin 190
When the cylindrical piston 120 of the control valve 102 is steered to shift rightward, the circular valve piston 135 of the left circular valve 103 is simultaneously raised by the pin 191 in the opposite direction. . This results in ring-shaped 3
The groove 132 is in communication with the annular groove 133, so that the inlet groove 12 of the control valve 102 can be accessed via the inlet passages 142 and 143.
2 and 123 are also loaded by accumulator pressure. The rightward movement of the control piston 120 then closes the control edge 129 and opens the control edge 130, so that the pressure chamber 172 becomes loaded with accumulator pressure via line 113. At this time, servo piston 1
70 via line 112, open control edge 128 and return line 111 to unloaded pressure chamber 1
Pressure medium from 71 is displaced into tank 108 . As described above with respect to the embodiments, in the cage pressure actuated power steering system of the present invention, the pin provided on the steering handle shaft is directly engaged with the valve piston of the control valve, thereby directly sliding the valve piston. Since the structure is simple and reliable operation can be obtained, a conical valve is used to cut off the supply of oil from the pressure gauge to the control valve. It has a simple structure in which a valve seat is formed inside a sleeve in which a pair of annular grooves 1 are bored, and a circular piston is simply inserted into the valve seat so as to be in contact with the valve seat. This has the advantage of being easy to manufacture and making the device inexpensive overall.

By simply forming an annular groove in the sleeve of the circular valve, it is possible to form a pressure oil passage that passes through the inside and outside of the sleeve, enters the sleeve from outside the sleeve, and goes out again to the outside of the sleeve. Since the valve is constructed by simply inserting a circular piston into the sleeve, the case itself only needs to be machined with a passage that connects to the two annular grooves of the sleeve and a sleeve insertion space, which simplifies the machining and structure. can be measured. Further, since the buffering effect when the valve is operated can be obtained by simply forming a hole in the sleeve wall, the structure can be simplified in this respect as well.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a control valve device having one sushi platter and a valve, and FIG. 2 is a cross-sectional view of the control valve device having two sushi platters and a valve. 1,101...control device, 2,102...
...Control valve, 3,103,203... Yen sushi, valve, 4,
104... Case, 5, 105... Servo pump, 6,
106... Pressure accumulator, 7,107... Servo motor, 8,108... Tank, 9,109... Torsion bar, 10,110... Inflow pipe, 1
1,111...reflux pipe line, 20,120...
・Valve piston, 21, 121...Valve sleeve, 22
, 23, 122, 123... Miso inflow 1,
27, 30, 127, 130...external control edge, 32
, 33, 132, 232... Annular groove of conical valve,
34,134,234...screw, 35,135,235
... Valve piston, 42, 43, 142, 143...
...Inflow passage, 90, 190, 191...Pin, 9
1... Support wedge, 92... Ball, 93...
・Bridge member. FIG. l FIG. 2

Claims (1)

[Claims] 1 Case 4; Control valve device provided inside 104 1; 1
01, and the pressure accumulator 6 via this control valve device 1; 101;
Double-acting servo motor for steering connected to 106; 10
7, a control valve 2; 102 and a conical valve 3; 103, 203 provided in the case 4; 104 so as to constitute the control valve device 1; 101;
102 has a valve piston 20; 120 housed in a bore inside the case 4; 104, which valve piston can be moved in two axial directions directly by means of a pin 90; The case 4; 104 has an inflow pipe 10; 110 from the pressure accumulator 6, 106 connected to the conical valve 3, 103;
03; and passages 42, 43; 142, 143 connecting the conical valve to the control valve;
passages 12, 13; 112, 113 providing communication with the control valve servo motor 7; 107; and control valve 2;
a return connection 45; 145 connecting the reflux line 11; 111 to the tank 8;
, 43; 142, 143;
, 23; 122, 123, and the reflux pipe 11; 1
11 are provided with fluid return grooves 24; 124, these grooves and the valve piston are connected in a neutral position of the valve piston;
the conical valve 3 being associated to cut off the supply of pressure fluid from the fluid inlet groove to the double-acting servo motor and to connect the non-pressure side of the servo motor to the return line;
103, 203 includes a biasing device 37; 137, 237 that biases the flow through the interior thereof to normally be blocked;
A conical valve actuating device 91, 92, 93; 191 is provided to interconnect the valve piston of the control valve and the conical valve, and this conical valve actuating device operates the valve via the pin 90; 190 by manual operation. configured to interlock a conical valve with a valve piston to open the conical valve against the force of the biasing device when the piston is displaced from a neutral position for supplying pressurized fluid to a servo motor; The conical valve has a conical valve piston 35; 135, 235 and its valve seat, and the conical valve piston has a part that constantly receives pressure from the pressure accumulator, and the pressure acting thereon normally causes the valve seat to 131, the conical valve piston being slidably housed within a sleeve 33; 131 and reciprocally guided within a portion of this sleeve, said portion having a damping perforation. a conical valve 3 of the inflow pipe 10; 110;
103, 203 is an annular groove 3 bored in the sleeve so as to communicate with the inside of the sleeve on the upstream side of the valve seat.
2; An annular groove 33; 133, 233, which is continuous with 132, 232 and is bored in the sleeve so as to communicate with the inside of the sleeve on the downstream side of the valve seat, connects the conical valve to the control valve; , 143.