JPS60183260A - Flow control device for power steering equipment - Google Patents

Abstract

PURPOSE:To prevent change in flow characteristics at low temperature by forming the second orifices which are inserted inside a passage connecting to a power steering device with small holes, and closing either one of the small holes at normal temperature and opening it at low temperature. CONSTITUTION:Flow fluid supplied from a supply passage 12 is supplied to the first valve room 32 through a control throttle 31 and then supplied to a power steering device from ejection port 21a of union 21 via a flow hole 23a and each of orifices 24a, 24b. In this case, when the temperature of flow liquid is low and viscosity of the fluid is high, difference in pressure between the front and rear of a control throttle 31 is caused due to increased throttle resistance of the control throttle 31, allowing a control spool 23 to slide and closing the first orifice 24a. Therefore, a control member 35, which consists of bimetal, selectively opens and closes either one of the multiple, small holes H1-H6. Decrease in flow rate caused by closing the first orifice 24a is then compensated for with increase of opening area of the second orifice 24b.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is directed to a flow rate system in which pressurized fluid discharged from a pump is sent to a power steering device through an orifice, and surplus flow is returned to the suction side through a bypass passage. This invention relates to a control device for a VJ/4 steering device that increases the flow rate sent to the power f1ε control device by 1 (a) as the rotational speed of the steering pump increases.

<Prior art> Conventionally, as a flow rate control device having two functions, a pressure difference is generated before and after the control throttle based on the 1v1 addition of the original discharge rate due to an increase in the pump rotation speed, and the control is performed using this pressure difference. 1st by displacing the spool. One side of the second orifice is controlled to open and close, and when the pump rotational speed N reaches a constant rotational speed as shown in FIG. 1, the discharge flow begins! i￥Q 1 squad-1・
Is there a way to do that?

However, according to such conventional devices, low 'l+! ! L
When the pressure increases the viscosity of the fluid, the throttle is controlled by
There was a problem in that the pressure difference between the thorns became large, and as a result, the control spool was displaced and the first orifice was closed, making it impossible to obtain the required flow rate characteristics as shown in FIG. 13.

The present invention was made in order to solve the above-mentioned conventional problems, and its purpose is to reduce the flow rate of the fluid regardless of the viscosity change of the fluid at low temperatures. The goal is to ensure that the characteristics do not change.

<Structure of the Invention> The present invention has been made to achieve the above object 1.
The second orifice is composed of a plurality of small holes, and a control member that closes any of the plurality of small holes at normal times (, 11) and opens at low temperature is used as +iii. This provision is a structural feature.

<Example> The embodiments of the present invention will be described above with reference to the drawings.

In Fig. 2, reference numeral O denotes a pump house sink, which is installed in the pump housing jO through the storage hole 11, and the union 21 is connected to -1111 of the storage hole 11.
A stopper 25 is fitted to the other end of the housing hole 11 in a tight manner of /1v.

The spool valve 22 is slidably inserted between the union 21 and the stopper 25 in the storage hole 11.
A first valve chamber 32 and a second valve chamber 33 are formed inside. Further, the spool valve 22 is biased by a spring 26 interposed in the second valve chamber 33 and comes into elastic contact with a control spool 23 (to be described later), and is connected to the supply passage 12 and the bypass passage 13 provided in the pump housing 10. Note that the bypass passage 13 communicates with the suction chamber of the fluid pump.

The control spool 23 is slidably inserted into the inner hole of the union 21, and has an orifice forming portion 4 fitted into the outer end of the inner hole of the union 21. The union 21 is biased by the spring 27 interposed between the t 24 and the
211] of the inner hole of the inner hole.

This control spool 23 is formed with a communication hole 23-1 that communicates the second valve chamber 32 with the control spool 23 and the empty space 34 between the control spool 23. Each orifice 24 of the orifice forming member 24 described later. ．． l.

24b, the first valve chamber 32 and the outlet port 2]a of the union 21 are communicated with each other. Further, a pressure introduction hole 21c provided in the union 21 is opened at the end surface of the stepped portion 23b of the control spool 23. This pressure introduction hole 21C communicates with the supply passage 2, and the supply pressure is maintained at a predetermined level. When the pressure is increased, the control spool 23 is caused to slide against the spring 27.

The orifice forming member 24 includes each orifice 24 described later.
．． A and 24b are also provided with a 1lill i wholesale nozzle 24C, and this control nozzle 24c connects the downstream side of each orifice 24a and 24b to a communication hole 21d provided in the union 21 and the pump housing sink 10.

It communicates with the second valve chamber 33 through 14. As a result, a part of the (&a side fluid of each orifice 24a, 24+) is guided into the second valve chamber 33, and the upper blades of the front and rear of each orifice 24.-1.24b act on both ends of the spool valve 22. and the differential pressure C1 before and after each orifice 242,241)
Then, the spool brake l22 moves in the axial direction]i1+
Bypass passage 1 to keep the differential pressure constant;
Adjust the opening degree of 3.

As shown in FIGS. 3 and 4, the orifice forming portion 24 has a first orifice 24 approximately in the center thereof.
a, and its first orifice 24. i
A second orifice 24b consisting of a plurality of small holes 1', l' H1 to H6 is formed on the outer periphery of the l. These first. Second orifice 24δ.

24b normally connects the first valve chamber 32 and the delivery D 2 ] a
The first orifice 24a is communicated with each other, and the movement of the control spool 23 closes the first orifice 24a.

Control portions i, t are provided on one end surface of the orifice forming member 24.
35 is pressed by the repulsive force of the spring 27, and the odd-numbered small holes 11], H3 are formed on the inner periphery of the control member 35.
, l-15, tongue pieces 35.1 are formed at appropriate intervals in the circumferential direction.

The control member 35 is made of a bimetal or the like, and is configured to adjust the temperature of the tongue 35 depending on the temperature of the fluid passing through the second orifice 24b. The shape of l changes, for example,
When the temperature of the fluid is the same as that of the product, the tongue piece 35a is in close contact with the end surface of the orifice forming portion 24 as shown in FIG.
, +43. When H5 is closed and the temperature is low, the tongue piece 3.52 deforms toward the control spool 23 as shown in FIG. 5 and closes the small holes 1-11 and I-13.

[It is now possible to open +5.]

+iii 11-Nion 21 has a 1118 cylindrical shape,
The inner end thereof is loosely connected to the storage hole 11, and a control throttle 31 is formed between the outer circumference of the inner end and the inner circumference of the storage hole 11, and a control throttle 31 is connected to the supply passage 12 through the control throttle 3]. It communicates with the first chamber 32. This control aperture 31
is in the supply passage 12 (j).
A vacant chamber (3
4, the control spool 23 is displaced in the axial direction in response to this pressure difference.

In the flow rate control device configured as described above, when the fluid pump is driven by the vehicle engine, fluid is supplied from the discharge chamber of the fluid pump to the supply passage 12.

The supplied J fluid passes through the 11 control throttle 31.
is supplied to the first valve chamber 32 and from the first valve chamber 32 to the communication hole 23.
a and each orifice 24a.

24, Union 21 sending out III 21 a via b
The power is then fed to the power steering system.

However, if the rotational speed of the fluid pump is low, make it!
Since the discharge flow rate of J) fluid is small, the spool valve 22 closes the bypass passage 13 and supplies the entire amount of working fluid to the J) J rI sampling device through each orifice 24a, 24b. When the discharge flow rate of the working fluid increases in response to an increase in the rotational speed of the fluid pump, the spool valve 22 does not maintain a constant differential pressure across the orifices 24a and 24b.
Then, the bypass passage 13 is opened, and the surplus flow of the J fluid is returned through the bypass J passage 13 to the suction chamber of the -C fluid pump. As a result, the working fluid is supplied to the power fj collector device: 1, each orifice 24a, 24. χ i11S1 for a predetermined 'LfiQl not shown in FIG.
be done.

Furthermore, as the vehicle starts to run at high speed, the rotational speed of the fluid pump further increases and the discharge flow rate of the working fluid supplied to the supply passage 12 increases. Due to the resistance, the fluid pressure in the supply passage 12 increases,
There is a pressure difference between the supply passage 12 and the first valve chamber 32, and at the same time, the pressure in the supply passage 12 acts as a pressing force that causes the control spool 23 to slide against the spring 27 through the pressure introduction hole 21C. do. Therefore, when the pressure in the supply passage 12 increases to 1111 times the biasing force of the spring 2■ in response to an increase in the discharge flow rate of the working fluid, the control spool 2 (
3 slides 1111 times against the spring 27, and finally the first orifice 24a is completely closed.
The flow rate Q2 determined by the orifice 24b is maintained.

By making the control spool 23 in this manner, the vehicle can run at low speed i]11; Transition to 11': By gradually reducing the flow rate supplied to the power steering system, the steering wheel operation becomes gradually heavier, allowing high-speed and low-speed T-shifting without causing any discomfort to the driver. Having sex - I can do something.

By the way, if the pressure fluid is always 61 hours, a single flow rate characteristic can be obtained as described above, or if the temperature of the fluid is low, such as at the start of operation, the viscosity of the fluid is high, so the control throttle 3 'The aperture resistor is in front of the control aperture 31 (in front of the control aperture 31)
As a result, the control spool 23 moves and the first orifice 24a is closed, causing the required flow (r( [The protection is lost.

However, in the present invention, the system consisting of "C" and "High Notar" falls
By r'5lI4A 3 s, multiple small holes 111~
Chairs H6 and 11 can be selectively opened and closed by C5. When the fluid is at room temperature, as shown in FIG. 3, the small hole is +11.03.
1-(5 is closed and the second orifice 24I) is occupied 35. ] or as shown in Figure 5, when the area is small, the fluid is low? , and open all the small ('Lllll~H6, resulting in the second
The open area of the orifice 241) becomes larger.

Therefore, even if the first orifice 24a closes due to the movement J of the control spool 23 and the flow rate decreases, the decrease in flow rate is compensated for by the increase in area of the second orifice 24b (-1), so the overall Flow rate reduction is prevented and 1
This enables easy flow control.

<Effects of the Invention> 1-Description As described in detail, the present invention comprises a second orifice composed of a plurality of small holes, and any one of the plurality of small holes is closed at room temperature and opened at low temperature. Since the control section 21 is provided at the openings of the plurality of small holes, there is an advantage that the flow rate characteristics can be prevented from changing regardless of changes in the viscosity of the flowing fluid at low temperatures.

[Brief explanation of the drawing]

The drawings show an actual example of the present invention, and FIG. 1I21 is a graph showing the flow rate characteristics with respect to the pump rotation speed, FIG. E
=R is enlarged by Flt indicating the main part of the control device.
A side view, Figure 4 is a sectional view taken in the direction of arrow 1 in Figure 3, Figure 5 G, 1
FIG. 6 is a main part IJ and li side view showing a deformed state of the control member. 12... Supply passage, 13... Bypass passage, 22...
...Spool 11ゝ, 23...Control spool, 24a
... 1st orifice, 24b... 2nd orifice,
31... Control aperture, 35... Control 1al (+A, o
l ~+-+ 6 ・-small hole. Patent applicant Toyota Ue (Iku Co., Ltd. Figure 4 H1

Claims (1)

[Claims] (1) A control throttle is inserted into the supply passage leading to the pump,
First and second orifices are inserted in the passage leading from this supply passage to the 1st and 2nd orifices, and the flow rate εIX (pressure regulating spool 'Jr is displaced -U to adjust the opening degree of the bypass passage that recirculates the excess fluid to the suction side of the pump by gE+, and (11
1. In response to the pressure difference before and after the control throttle, the control spool is displaced to control the first manifold flow control device.
The second orifice is composed of a plurality of small holes, and one of the plurality of small holes is 6111111! A control i'41 which closes at J and opens at low/l'lA is provided at the opening L:I'r++ of the plurality of small holes marked 5'+i'+. Meteor control device for ``Power Steering Device i''.