JPS6330613Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a fluid control valve device used in a power steering device for reducing the steering force of an automobile, and in particular, it has a rotor and a sleeve, and the relative rotational displacement of the rotor and sleeve causes fluid pressure to increase. The present invention relates to a rotary fluid control valve device that distributes and controls fluids.

This type of fluid control valve device is used to operate the power cylinder, which is the movable part of the power steering device, in response to steering wheel operation, and to generate auxiliary force during steering operation. By forming a plurality of passage grooves in the groove and guiding passages into each of these passage grooves to communicate with the left and right cylinder chambers on both sides of the piston that constitute the oil pump, oil tank, and power cylinder, hydraulic oil is It is widely used because it allows easy and reliable flow path switching and has a simple configuration.

However, this type of fluid control valve device has a problem in that it generates noise during control, that is, during valve operation, and it is desired to have a structure that can eliminate this problem. That is, when the valve is actuated, the flow path is switched and the hydraulic oil that is guided from the oil pump to the passage groove of the rotor via the entry port is sent from the passage groove of the sleeve to one of the cylinder chambers via the outlet port. However, in this case, the excess hydraulic oil is guided from the passage groove of the sleeve to the passage groove of the rotor that communicates with the return port, and is sent from this return port to the oil tank side. At this time, the pressure difference between the fluid pressure on the inlet port side and the fluid pressure on the return port side is large, and the pressure of the hydraulic oil led to the return port changes rapidly, which affects the rotor and sleeve and causes noise. arise.

For this purpose, the present applicant first proposed a fluid control valve device for a power steering device in Japanese Patent Publication No. 50-30336, which can eliminate the sudden pressure change during valve operation and reduce noise. are doing. To explain this simply, this fluid control valve device has a low resistance passage connecting an entry port and a return port by passage grooves formed in the rotor and sleeve, and a passage provided on the axial side of this low resistance passage. The high-resistance passage is formed by a nozzle or multi-stage throttle formed between the rotor and the sleeve, and when the valve is operated, the low-resistance passage is blocked, and the high-pressure fluid generated on the inlet port is diverted to the high-resistance passage. By guiding the fluid pressure to the return port side through the passage, the fluid pressure is divided and dropped in stages so that sudden pressure changes do not occur.

However, such a structure requires strict machining accuracy for the nozzle or multi-stage constriction part that constitutes the passage with high resistance, which makes the machining work troublesome, and has the disadvantage of being difficult to achieve precision and increasing costs. Ta. Furthermore, due to the above-mentioned configuration in which the passages with high resistance are arranged side by side on the axial side of the passages with low resistance, there is a problem that the length of the entire valve device in the axial direction becomes long, making it impossible to make it compact.

Another idea is to form an orifice on the circumferential side edge of the passage groove formed in the rotor and sleeve, and use this orifice to increase the pressure on the return port side when the valve is activated and reduce the pressure change. However, such a structure affects the fluid pressure sent to the cylinder chamber side, resulting in a drop in effective pressure, which is unfavorable for its operation.Furthermore, the orifice shape is limited, and machining accuracy is required. It was hot.

In view of these circumstances, the present invention provides a first chamber between the high-pressure chamber on the inlet port side and the low-pressure chamber on the return port side, which are generated when the valve is operated, to communicate only these two chambers sequentially.
A second passage groove is formed facing the fitting surfaces of the rotor and the sleeve to form an intermediate pressure chamber, and a gap is used to communicate the intermediate pressure chamber and both chambers during valve operation. By using a simple configuration that gradually reduces the fluid pressure to the return port side and buffers it, it is possible not only to eliminate sudden pressure changes between the high pressure side and the low pressure side when the valve is activated, but also to reduce noise. , it has no effect on the effective pressure on the inlet port side, ensures reliable valve operation, has a simple configuration of each part, does not require high machining accuracy, and has a compact overall configuration. The present invention provides an inexpensive fluid control valve device that can be used.

Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

FIG. 1 shows a schematic configuration of a power steering device to which a fluid control valve device according to the present invention is applied. This will be briefly explained in the figure. Reference numerals 1 and 2 are a steering body and a housing that closes the opening thereof. A piston 4 constituting the power cylinder 3 is slidably disposed in the internal space, and left and right cylinder chambers 5 and 6 are formed on both sides of the piston 4. Note that 7 is a sector shaft that is interlocked with the steering device, and its sector gear 7a meshes with the rack 4a of the piston 4.

Reference numeral 8 denotes a stub shaft serving as an input shaft that is rotated by operating the handle, and this stub shaft 8 is disposed to penetrate inside the housing 2. A wormshaft 9 is disposed coaxially with the right end of the stub shaft 8. The right end of the wormshaft 9 is screwed into the piston 4, and its rotation moves the piston 4 in the axial direction. It is configured as follows.

A torsion bar 10 is disposed coaxially within the stub shaft 8 and the worm shaft 9, and its both ends are fixed to the shafts 8 and 9, respectively. The stub shaft 8 and the worm shaft 9 rotate independently of each other within a predetermined angle range due to the action of the torsion bar 10, and rotate integrally once this angle is exceeded.

Reference numeral 11 denotes a fluid control valve device that distributes and controls hydraulic oil from an oil pump (not shown) to the left and right cylinder chambers 5 and 6 of the power cylinder 3, and this fluid control valve device 11 is integrated with the stub shaft 8. It includes a rotor 12 that rotates independently, and a sleeve 13 that is disposed around the rotor 12 and rotates integrally with the worm shaft 9. The fluid pressure passage is switched by rotational displacement. In this case, the rotor 12 is integrally formed with the stub shaft 8 and the sleeve 13 is shown in the figure.
is fixed to the right end of the wormshaft 9 via a pin 14.

The rotor 12 enters the outer periphery of the rotor 12 and enters the port 15.
The sleeve 13 has two types of passage grooves 17 and 18 that communicate with the return port 16, and the sleeve 13 has two types of passage grooves 17 and 18 that communicate with the passage grooves 17 and 18 selectively on the inner circumference of the sleeve 13 to allow hydraulic oil from the entry port 15 to flow through the passage grooves 17 and 18. Passage grooves 19 and 20 leading to the left and right cylinder chambers 5 and 6 are formed. That is, these passage grooves 19 and 20 are provided with passages 21 and 2 formed in the radial direction of the sleeve 13.
2 is open, and one passage 21 is connected to the sleeve 1.
A gap between a bearing 23 that pivotally supports the cylinder 3 is communicated with the right cylinder chamber 6 via a passage 24 that serves as an output port. Further, the other passage 22 is connected to the sleeve 13.
It communicates with the left cylinder chamber 5 through an annular passage 25 on the outside of the housing 2 and through passages 26 and 27 in the steering body 1, which serve as another output port. Note that 28 is an annular passage communicating with the entry port 15 via a passage 29, and this annular passage 28 communicates with the passage groove 17 of the rotor 12 through a passage 30 formed in the radial direction of the sleeve 13. Further, 31 is an annular passage formed on the side of the sleeve and communicating with the return port 16 via a passage 32;
It communicates with the other passage groove 18 of the rotor 12 by a passage 33 bored in the radial direction of the rotor 12, an internal passage 34 of the rotor 12, and a passage 35 bored in the radial direction in the center of the rotor 12. There is.

In such a configuration, when the handle is in the neutral position, the pressure in the left and right cylinder chambers 5 and 6 is kept constant by the action of the fluid control valve device 11, and the piston 4 receives an axial operating force. maintain a neutral position.

Further, when the handle is operated, the stub shaft 8 and the worm shaft 9 are rotated in the operating direction, thereby moving the piston 4 in the axial direction, and at the same time, the fluid control valve device also switches the hydraulic circuit, The resulting differential pressure between the left and right cylinder chambers 5 and 6 exerts an axial operating force on the piston 4, and the operating force due to this oil pressure reduces the above-mentioned handle operation force.

Now, according to the present invention, when the valve of the fluid control valve device 11 described above is operated, a portion of the hydraulic oil flowing in from the inlet port 15, that is, an amount greater than the amount of hydraulic oil necessary to move the piston 4 in accordance with the handle operation. In order to reduce the noise generated by circulating the hydraulic fluid back to the return port 16 side, an intermediate pressure chamber is provided in the middle of the flow path, thereby buffering the fluid pressure. That is, when the valve is operated, the hydraulic oil sent from the inlet port 15 to the passages 24 or 26, 27 constituting the output port is in a high pressure state, while the return port 16 side communicating with the oil tank (not shown) is in a high pressure state. Due to the low pressure state, a sudden pressure change occurs, which causes noise, and the present invention is designed to eliminate this sudden pressure change.

To explain this in detail with reference to FIGS. 2 and 3, 12 passage grooves are formed on the outer periphery of the rotor 12 at appropriate intervals in the circumferential direction, and on the other hand, on the inner periphery of the sleeve 13. Corresponding to this, 12 passage grooves are formed. The passage grooves on the outer circumference of the rotor include a passage groove 17 in which a passage 30 communicating with the inlet port 15 is opened, a passage groove 18 in which a passage 35 communicating with the return port 16 is opened, and these passage grooves 1.
3 with the first passage groove 40 formed between 7 and 18.
Consists of types. Further, the passage groove of the sleeve 13 is a passage 21 that communicates with the left and right cylinder chambers 5 and 6.
The passage grooves 19 and 20 with openings 22 and the rotor 1
There are three types of second passage grooves 41 that face and form a pair with the second new passage groove 40. In this case, the illustrated embodiment shows a type of valve device having three sets of switching portions at three locations in the circumferential direction.

Here, it should be noted that when the hydraulic oil flowing from the oil pump P through the passage 30 into the passage groove 17 of the rotor 12 is sent to the oil tank T through the passage groove 18 and the passage 35, Groove 1
New passage grooves 40 and 4 of the rotor 12 and sleeve 13 formed to be located between 7 and 18
1. This means that it flows through a space formed by 1.
When the valve is operated as shown in FIG. 3, this space is connected to the passage groove 17 of the rotor 12 and the passage groove 19 of the sleeve 13, which become the high pressure chamber 42 on the oil pump P side, and the low pressure chamber 43 on the oil tank T side. Intermediate pressure chambers 46 are formed in communication with the passage grooves 18 of the rotor 12 through desired gaps 44 and 45, respectively. That is, the hydraulic oil that flows from the high pressure chamber 42 into the intermediate pressure chamber 46 via the gap 44 and is further sent to the low pressure chamber 43 via the gap 45 flows through the gap 44,
45, the fluid pressure can be lowered in stages, and this intermediate pressure chamber 46 has a function of buffering sudden pressure differences. By adopting such a configuration, there is no sudden pressure change during valve operation, and as a result, it is possible to reduce noise. In this case, the gap 44 communicating with the high pressure chamber 42 is connected to the low pressure chamber 4
If the gap is set to be smaller than the gap 45 on the third side, the buffer function in the intermediate pressure chamber 46 can be effectively performed.

Note that when the valve is operated as shown in FIG. 3, the passage 22 to the left cylinder chamber is separated from the oil pump P side, and the hydraulic oil flows into the left cylinder chamber from the passage 22 to the aforementioned intermediate pressure chamber 46 of the rotor 12 and sleeve 13. The oil is sent to the oil tank T side through the passage grooves 40 and 41 on the side where the oil is not formed. here,
What should be noted is that the left cylinder chamber on the opposite side to this switching direction is recirculated to the return port side regardless of the above-mentioned intermediate pressure chamber 46, so that appropriate output on the power cylinder 3 side can be maintained. This has the advantage that it can be appropriately and reliably secured with the minimum necessary pump pressure. Even when a switching operation opposite to that shown in FIG. 3 is performed, an intermediate pressure chamber is formed in the same manner as described above, and the pressure change is of course buffered.

In addition, in the above-mentioned embodiment, a type having three sets of switching parts in the circumferential direction of the valve was described, but the present invention is not limited to this.
As shown in the figure, it may be provided in two sets of switching parts in the circumferential direction, in short, it is located between two types of passage grooves that communicate with the entry port and the return port of the rotor, and communicates with the rotor. If first and second passage grooves are provided in pairs on the fitting surface with the sleeve, thereby forming a portion that becomes an intermediate pressure chamber in the middle of the flow path toward the return port side when the valve is operated. It's good.

Further, the present invention is not limited to the structure shown in the embodiments described above, and it goes without saying that the configuration of each part can be changed as appropriate without departing from the gist of the present invention.

As explained above, according to the fluid control valve device according to the present invention, the first and second valves are provided in succession between the fitting surfaces of the rotor and the sleeve in the middle of the flow path from the inlet port to the return port. A space formed by the passage groove of No. 2 is formed, and this space is made into an intermediate pressure chamber that communicates with the high pressure side and the low pressure side through a gap when the valve is operated, so that various effects listed below can be achieved. play.

(1) The intermediate pressure chamber eliminates sudden pressure changes during valve operation and reduces fluid pressure in stages to buffer pressure differences, making it possible to minimize noise generation. .

(2) An intermediate pressure chamber is formed by a pair of passage grooves parallel to the normal passage grooves formed in the circumferential direction of the rotor and sleeve, and the relative rotational displacement between the rotor and sleeve allows pressure to move between the high pressure side and the low pressure side. Since a communicating gap is formed, the structure is simple, machining accuracy is not required, and the cost is low because it can be easily machined, and two resistance passages are provided in the axial direction as in the conventional method. Thereby, the length in the axial direction can be shortened and the entire valve device can be made compact.

(3) In addition, since the intermediate pressure chamber can reliably buffer pressure changes during valve operation, it does not affect the fluid pressure to the output port side and does not impair its operational performance. The shape of the orifice is not limited and can be freely selected.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing a schematic configuration of a power steering device to which a fluid control valve device according to the present invention is applied;
The figure is a cross-sectional view of a main part showing one embodiment of the fluid control valve device according to the present invention, FIG. 3 is an enlarged view explaining its operating state, and FIG. It is a diagram. 11... Fluid control valve device, 12... Rotor, 1
3... Sleeve, 15... Entry port, 16...
Return port, 17, 18... Passage groove, 19, 20
... Passage groove, 21, 22 ... Passage (output port side), 30 ... Passage (input port side), 35 ... Passage (return port side), 40, 41 ... Pair of passage grooves, 42 ... High pressure chamber, 43...Low pressure chamber, 44,4
5...Gap, 46...Intermediate pressure chamber.

Claims (1)

[Scope of utility model registration request] A rotor having two types of passage grooves in the circumferential direction that communicate with an inlet port and a return port, and a rotor that is fitted around the rotor and selectively communicates with the passage grooves of the rotor to output two types of fluid. A sleeve is provided with a passage groove in the circumferential direction leading to the port, and the flow path is switched by relative rotational displacement between the rotor and the sleeve to send fluid from the inlet port to one output port side and a part of the fluid. In a fluid control valve device that guides the output port to the return port side and connects the other output port side to the return port side, one passage groove located between the two types of passage grooves on the rotor side and leading to the output port of the sleeve. A first passage groove that communicates with the rotor is formed on the fitting surface of the rotor outer periphery, and a second passage groove that communicates the first passage groove with a passage groove that connects to the return port side of the rotor. , a high pressure chamber on the inlet port side formed on the fitting surface of the inner periphery of the sleeve, and formed on one passage groove side of the sleeve when the valve is operated by the first and second passage grooves, and the rotor. 1. A fluid control valve device comprising an intermediate pressure chamber that selectively communicates with a low pressure chamber formed by a passage groove toward a return port side through a desired gap.