JPS61291227A - Cylinder apparatus for car speed controller for vehicle - Google Patents

Abstract

PURPOSE:To smoothly and correctly control the speed of a car by forming an orifice for the communication between two cylinder chambers divided by a piston onto the piston of the captioned cylinder apparatus and installing an orifice opening/closing means. CONSTITUTION:When a brake pedal 25 is stepped in, a hydraulic pressure is generated in a brake master cylinder 21 connected to the piston 19 of a cylinder apparatus 17 through a piston rod 32, and said hydraulic pressure is supplied into the brake cylinder for a wheel 1 through a brake pipe 22, and brake operation is performed. The oil in the flow rate corresponding to the car speed is introduced into a cylinder chamber 18a from a pump 12 by the cylinder apparatus 17 when a car retreats, and in case of the flow rate over a limit value due to the orifice 27 formed onto the piston 19, the piston 19 moves rightward, and brake operation is performed. When the piston 19 shifts to a right limit, and an opening/closing pin 28 moves leftward, and an orifice 26 is opened, the piston 19 is returned to the original position by the residual pressure.

Description

Detailed Description of the Invention The present invention relates to a speed control device for automatically controlling a vehicle such as an automobile so that the vehicle speed does not exceed a certain speed, and particularly relates to such a speed control device. The present invention relates to a cylinder device.

In vehicles equipped with a reversing mechanism, such as front and rear vehicles or self-driving three-wheeled vehicles, the driver turns his head toward the rear and checks what is behind him when reversing, so the faster the reversing speed, the faster the driver can drive. Consideration should be given to ease of driving when reversing as the burden on the driver is heavy.Ii
! Then, it is desirable to prevent the reverse speed (reverse speed) from increasing above a certain value.

For this reason, conventionally, a three-wheeled motor vehicle with a reverse mechanism is provided with a vehicle speed limiting device that is activated by detecting a reverse operation, and the device limits the reverse vehicle speed to a predetermined value or less. No. (JP-A-59-155545
(No.). The vehicle speed limiting device includes a vehicle speed detection circuit that detects vehicle speed, a reverse detection circuit that detects reverse operation, and a discrimination circuit that discriminates signals from both detection circuits and generates an output signal when the vehicle speed exceeds a predetermined vehicle speed during reverse operation. and an ignition stop circuit that stops the operation of the engine's ignition system based on the output signal from the discrimination circuit. The vehicle speed is limited to a predetermined vehicle speed or higher.

In addition, the present inventors did not provide various electronic circuits and control the engine etc. through signals from these circuits as in the conventional device described above to limit the vehicle speed, but rather directly and In order to effectively limit the vehicle speed to a predetermined value or less, a pump is provided that discharges fluid with a predetermined cover in response to the vehicle speed in one direction or the opposite direction depending on whether the vehicle is moving forward or backward. A vehicle speed control device in which a wheel braking device is actuated by fluid discharged from
It is proposed by No. 23/1168. In this vehicle speed control device, fluid discharged from the pump is guided through a brake conduit to a cylinder device, and from the cylinder device is further returned to an oil tank through a discharge conduit, and an orifice is provided in the discharge conduit. J3, the flow rate flowing back to the oil tank is restricted by this orifice. Therefore, when the vehicle speed is low and the discharge flow rate of the pump is small, the fluid discharged from the pump returns to the oil tank as it is, and no pressure is generated within the cylinder device to operate the piston. However, when the vehicle speed increases above a certain value and the discharge flow rate of the pump exceeds the flow limit defined by the orifice, the pressure within the cylinder device increases and moves the piston. The movement of this piston activates the wheel braking device, which limits the vehicle speed to a certain speed or less.

However, in this vehicle speed device, a constant flow rate determined by the orifice of the discharge fluid sent from the pump to the cylinder device always flows out from the cylinder device. As a result, the force with which the piston of the cylinder device is pressed is reduced by that amount, making it difficult to perform quick braking.

If the opening area of the orifice is made smaller, the piston will move more easily and a faster braking action can be achieved, but the piston will not return easily when the brake is released due to residual pressure. Therefore, in order to obtain smooth braking action, the opening area of the orifice must be carefully determined in accordance with the outflow characteristics of the pump.

In order to reduce ρ1 to 1, the present invention aims to improve the cylinder device used in the above-mentioned width speed control 6Il device so as to be able to perform smoother and more reliable control. be.

For this reason, the cylinder device of the present invention includes a cylinder having an inlet for pump discharge fluid at one end and an outlet for the fluid at the other end, and a cylinder that is slidably fitted into the cylinder and has an inside of the cylinder. It is composed of a piston that is divided into a cylinder chamber on the inlet side and a cylinder chamber on the outlet side, and the piston is provided with an orifice that communicates the two cylinder chambers, and when braking is applied, the orifice is at least partially closed to release the brake. Sometimes an orifice opening/closing means is provided to open the orifice.

According to the present invention, the discharge fluid sent from the pump to the cylinder device flows into the cylinder chamber on the inlet side through the inlet provided at one end of the cylinder, and then passes through the orifice provided in the piston. It flows into the cylinder chamber on the outlet side with a predetermined outflow determined by the opening area of the orifice, and flows out from the outlet provided at the other end. When the vehicle speed increases and the discharge flow rate of the pump exceeds the flow rate defined by the orifice, the piston is moved by the discharge fluid accumulated in the cylinder chamber on the outlet side to operate the wheel braking device. When the wheels are braked in this way, the vehicle speed decreases, and the pump discharge flow rate also decreases, the piston returns to its original position.

Therefore, in the present invention, since the orifice opening/closing means for opening and closing the orifice is provided, by appropriately opening and closing the orifice with this orifice opening/closing means, the reciprocating movement of the piston can be performed smoothly as desired. can. In other words, the total opening area of the orifice is
The orifice is selected to allow a larger flow rate than the outflow corresponding to the maximum vehicle speed to be restricted, and the specified flow rate is obtained by partially closing this orifice at all times. The above return stroke (at the time of brake release)
If the orifice is configured to listen, the flow rate of fluid flowing through the orifice from the cylinder chamber on the inlet side to the cylinder chamber on the outlet side increases, so that the residual pressure in the cylinder chamber on the inlet side rapidly decreases. The piston can quickly return to its original position. Alternatively, if an orifice having a predetermined flow d characteristic corresponding to the maximum vehicle speed to be restricted is closed during the braking stroke of the piston (when applying control vJ), the fluid escaping through the orifice to the exit side can be closed. Since the flow area becomes extremely small, almost all of the discharge fluid flowing into the cylinder chamber on the inlet side is effectively absorbed by the screw 1.
- The piston moves quickly and provides smooth and reliable braking action. Of course, in the return stroke, the orifice is opened to allow the piston to return quickly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to illustrated embodiments. FIG. 1 is a schematic diagram showing the entire speed control device to which the present invention is applied.
1 is the left and right wheels. These wheels 1, 1 may be the rear wheels or front wheels of a normal automobile, or may be a pair of left and right wheels of a three-wheeled motor vehicle. 2 is a differential gear device, which is composed of a differential gear box 3, a small differential gear 4, and a large differential gear 5. A large reduction gear 6 coupled to the differential #J wheel box 3 is installed on the propulsion shaft 8. It meshes with the reduced speed reduction gear 7.

The large differential gear 5 is connected to the heavy wheels 1 via an axle 9, and the rotation of the propulsion shaft 8 is transmitted via the differential gear device 2 to both axles 1.
1.

A pump drive gear 10 is also meshed with the reduction large gear 6, and the tooth width 10 is connected to the pump 12 via a pump drive shaft 11.
is connected to the rotor of A one-way clutch 13 is inserted in the middle of the pump drive shaft 11, and this one-way clutch 13 drives the pump as shown by arrow a in the figure. When the F7I gear 10 rotates in the forward direction, it is released to cut off the transmission of rotation to the pump 12, and when the wheel 1 rotates in the reverse direction indicated by the arrow J: it engages to increase the pump drive tooth width 10. The rotation is transferred to the pump 1 via the pump drive shaft 11.
2. Therefore, the pump 12 operates only when the vehicle is traveling in reverse.

The pump 12 is a rotary pump such as a trochoid pump or a gear pump, and when the rotor is rotated by the pump drive shaft 11, oil is sucked from the reservoir tank 14 through a suction pipe 15 and discharged to a discharge pipe 16.

The discharge flow portion changes depending on the rotation speed of the pump drive shaft 11 and therefore the vehicle speed, and increases as the vehicle speed increases, but the rate of increase in the discharge flow ω relative to the increase in vehicle speed may be constant, or may gradually increase or decrease. You can do it like this. The discharge pipe 16 is connected to a cylinder device 17. This cylinder device 17 consists of a cylinder 18 and a piston 19,
The discharge pipe 16 opens at one end of a cylinder 18, and the other end of the cylinder 18 is connected to a return pipe 20. The inside of the cylinder 18 is divided by the piston 19 into a cylinder chamber 18a on the discharge pipe 16 side and a cylinder chamber +8b on the return pipe 20 side, and both chambers 18a.

18b communicates with the J: sea urchin, which will be described later, through an orifice provided in the screw 1 hem 19. Therefore, the flow rate of the oil discharged into the discharge pipe 16 is restricted by the orifice, but the flow rate of the oil discharged into the discharge pipe 16 is limited by the orifice, but the flow rate of the oil discharged into the discharge pipe 16 is limited by the orifice. The liquid is then stored in the aforementioned reservoir tank 14.

The piston 19 is connected to the brake mask cylinder 2 as shown in the figure.
1, and the piston 19 is connected to the arrow C.
By moving in the direction, the brake mask cylinder 21
Hydraulic pressure is generated inside the vehicle, and the hydraulic pressure is sent through the brake pipe 22 to a brake member attached to the wheel 1, such as a brake caliper (not shown), so that the wheel 1 is braked.

In this embodiment, the piston 19 is also interlocked with an operating member 25 such as a brake pedal, and the cylinder device 17 is used as a cylinder device of a normal braking device when traveling forward, and as a cylinder device of a speed control device when traveling backwards. It is designed to function as a cylinder device.

FIG. 2 is a sectional view showing details of the cylinder device 17.

An oil inlet 23 communicating with the discharge pipe 16 is provided at one end of the cylinder 1B, and an oil outlet 24 communicating with the return pipe 20 is provided at the other end.

The piston 19 is provided with orifices 26, 27, which are always in communication. Orifice 2
6 is an opening/closing pin 2 that constitutes a part of the orifice opening/closing means.
8 has been inserted. A protrusion 29 is provided on the side of the opening/closing pin 28 , and the piston 19 is moved radially into and out of the hole of the orifice 26 by a spring 29 to engage with the protrusion 29 . A lock type 31 is provided to suppress movement in the axial direction. piston 19
is connected to the piston of the brake mask cylinder 21 via the screw rod 32 as described above, and is pressed to the left in the figure by the spring built into the brake mask cylinder 21, so that the cylinder chamber 18a
When sufficient pressure is not present in the left device shown by the solid line in the figure, the bulging head 33 of the opening/closing pin 28 collides with a stopper 34 protruding from the inner end surface of the cylinder chamber 18a, Bottle 28 is pushed into orifice 26. Then, the head 33 closes the orifice 26, and this state is maintained by the engagement of the locking die 31 and the projection 29.

When the vehicle is moving backwards, the oil that has been sent into the cylinder chamber 18a from the pump 12 at a flow rate corresponding to the vehicle speed escapes to the cylinder chamber 18b through the orifice 27, which is always in communication, and then passes through the return pipe 20 from the outlet 24. It flows slowly into the reservoir tank 14. Therefore, when the discharge flow rate of the pump 12 is small and is below the limit flow rate defined by the orifice 27, no substantial pressure is generated in the cylinder chamber 18a, so the piston 19 does not move and the wheel 1 increases. When the discharge flow rate increases and becomes less than the flow rate limited by the orifice 27, the pressure inside the cylinder chamber 18a rises due to the oil accumulated in the cylinder chamber 18a, and the piston 19
The brake mask cylinder 21 moves to the right in the figure against the force of the built-in spring, and the wheel 1 is braked via the brake mask cylinder 21.

When the piston 19 reaches the right position shown by the broken line in the figure, the stopper 35 protruding from the inner end surface of the cylinder 18 causes the opening/closing pin 28 to protrude leftward from the orifice 26, so that the orifice 26 is opened. And the protrusion 29 is lock type 31
pin 28 is held open during this time, allowing fluid in cylinder chamber 18a to pass through both orifices 26, 27 and into cylinder chamber 18a.
It flows out to the side. Therefore, the pressure in the cylinder chamber 18a decreases, and the cylinder 19 quickly returns to its original position without resistance due to the residual pressure.

3 to 5 show other embodiments of the cylinder device of the present invention. The screws 19 normally occupy the left position shown in FIG. 3, as in the previous embodiment.

This piston 19 consists of a main piston 36 fixed to a piston rod 32, and a free piston 38 that is fitted around the outer circumference of the main piston and slides into contact with the inner surface of the cylinder 18 via a sealing ring 37. spring 3
9, the free piston 38 is urged to the right with respect to the main piston 36, and is supported by a collar ring 40 on the shaft 1 fixed to the main screw 1. The free piston 28 is provided with an orifice 41, and the entrance of the orifice 41 on the cylinder chamber 18a side is connected to a resilient plate-shaped opening/closing member 42 fixed to the main piston 36.
covered with. A narrow gap 4 is formed between this opening/closing part jrA42 and the entrance of the orifice 41.
3, the cylinder chamber 18a passes through the orifice 41.
The flow a of fluid flowing from the cylinder chamber 18b to the cylinder chamber 18b is restricted.

When the flow rate of the discharged fluid flowing from the pump 12 into the cylinder chamber 18a increases and exceeds the flow rate restricted by the gap 43, the piston 19 moves to the right in the state shown in FIG. The wheel 1 is braked via the cylinder 21 . When the piston 19 reaches the right end position of the cylinder 18, as shown in FIG.
It is displaced to the left relative to the main piston 36 against the force of. At this time, the opening/closing member 42 is pushed by the free piston 38 and deforms in a curved manner to the left as shown in the figure. Since the opening/closing member 42 is made of a dish-shaped elastic member as described above, the third
It has two stable states: a state where it is curved to the right as shown in the figure, and a state where it is curved to the left as shown in FIG. Therefore, the opening/closing member 42 that has been pushed by the free piston 38 and deformed as described above will not be able to move as shown in FIG. Maintain the same state and widen the gap 4
3, a relatively large amount of oil can flow from the cylinder 118a to the cylinder chamber 18b. Therefore, bis 1 hen 1
9 smoothly returns to the left position. When the left direction δ is reached, the opening/closing member 42 is deformed by hitting the end face of the cylinder 18, and is in a stable state curved to the right as shown in FIG. 3, and the gap 43 becomes narrow again.

FIGS. 6 to 8 show still other embodiments.

In this embodiment, screws 1 to 19 are attached to the piston body 4.
5, and inner screws 1~ slidably fitted on the outer periphery thereof.
46, and outer screws 1 to 47 which are slidably fitted around the outer periphery of the outer screw. Usually piston 1
9 is located at the left position shown in FIG. 6, and the inner piston 46
is pushed leftward by a spring 49 inserted between a retaining ring 48 fixed to the main body and received by a retaining ring 50. The outer piston 47 is located at a right position where it engages with a retaining ring 51 fixed to the right end of the inch piston 46, and the outer piston 47 is located at a right position where it engages with a stop ring 51 fixed to the right end of the inch piston 46. A gap 53 is formed between the left end surface of 47. The outer piston 47 has both cylinder chambers 18a at positions facing the opening/closing part C52.
An orifice 54 is provided that communicates with 18b.

When the flow rate of discharged oil flowing into the cylinder chamber 18a from the pump 12 exceeds the flow rate defined by the orifice 54, the inch piston 46 first compresses the spring 49 and moves to the right. At this time, the outer piston 47 has a small effective pressure receiving area, and the outer piston 47 has a small effective pressure receiving area, and
It does not move because of the large friction between it and the inner surface. Therefore, the orifice 54 is chained r'A by the opening/closing member 52, and thereafter, in this state, the entire piston 19 moves to the right as a unit, as shown in FIG. Since the orifice 54 is closed by the opening/closing piece 52 and the oil escaping from the cylinder chamber 18a to the cylinder chamber 18b disappears or becomes extremely small, the piston 19 quickly moves to the right.
Quick and reliable braking action can be obtained.

When the piston 19 reaches the right position, the movement of the piston body 45 and the inner piston 4G is prevented by the stopper 56, and the outer screws 1 to 4
7 moves to the right and engages with the retaining ring 51, again creating a gap 53 between it and the opening piece 52. As a result, the oil in the cylinder chamber 18a passes through the orifice 54 and flows to the cylinder chamber 18b side, so the piston 19 moves into the cylinder chamber 1.
It smoothly returns to the left position without being affected by the residual pressure inside 8a. At the time of return, the inner screw 1 hem 46 is displaced to the left position where it engages with the retaining ring 50 due to the spring 49, and is in a state similar to that shown in FIG. Note that the piston 19 is biased to the left by a spring built into the brake mask cylinder 21 (FIG. 1), as in the previous embodiments.

Above, an example in which the present invention is applied to an east and reverse speed control yD device has been described, but the present invention can also be applied to a forward speed control device. In addition, it goes without saying that the present invention is not limited to the above embodiments, and that many modifications can be made within the scope of the present invention.

As described above, the present invention receives fluid discharged from a pump that discharges fluid at a flow rate W that corresponds to the vehicle speed, and operates when the discharge flow rate of the pump exceeds a predetermined value to operate a wheel braking device. A cylinder device for a speed control device of a vehicle includes a cylinder having an inlet for the discharge fluid at one end and an outlet for the fluid at the other end, and the cylinder is slidably fitted into the cylinder and the inside of the cylinder is connected to the cylinder. It consists of a piston partitioned into a cylinder chamber on the inlet side and a cylinder chamber on the outlet side, and the piston is provided with an orifice that communicates the two cylinder chambers, and the orifice is at least partially closed when the brake is applied and when the brake is released. Since the orifice opening/closing means for opening the orifice is provided, by appropriately opening and closing the orifice with the orifice 17i1 opening means, the reciprocating movement of the piston can be performed smoothly as desired, and the speed of the vehicle can be smoothly and reliably maintained due to stiffness. can be controlled.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the entire speed control device to which the present invention is applied, FIG. 2 is a detailed sectional view of the cylinder device, and FIGS. 3 to 5 are each screw 1 in other examples. FIGS. 6 to 8 are partial sectional views of the cylinder device showing various states of the piston in still other embodiments. DESCRIPTION OF SYMBOLS 1...Wheel, 2...Differential gear device, 3...Differential gear box, 4...Differential small gear medium, 5...Differential large gear, 6...
... Reduction large gear, 7 ... Reduction small gear, 8 ... Propulsion shaft, 9 ... Axle, 10 ... Pump drive gear, 11 ...
・Pump drive II shaft, 12...pump, 13...one-way clutch, 14...reservoir tank, 15...
- Suction pipe, 16... Discharge pipe, 17... Cylinder device, 18... Cylinder, 19... Screws 1 to 20.
... Return pipe, 21 ... Brake mask cylinder, 22
...Brake piping, 23...Oil inlet, 24...
・Oil outlet, 25...operating member, 26, 27...
Orifice, 28...Opening/closing pin, 29...Protrusion, 3
0...Spring, 31...Lock style, 32...Piston rod, 33...Head, 34.35...Stopper 1.3
6...Main screw 1~n, 37...Sealing ring, 38.
...Free screw 1~n, 39...Spring, 40...Stopper ring, 41...Orifice, 42...Opening/closing member, 43...Gap, 44...S1~Brim, 45...・・・
Piston body, 46...Innabis 1~n, 47...
- Outer piston, 48... Retaining ring, 49... Spring, 50.51... Retaining ring, 52... Opening/closing piece, 53
... Gap, 54... Orifice, 55... Sealing piece, 56... Stopper.

Claims (1)

[Claims] A cylinder device for a speed control device of a vehicle that receives fluid discharged from a pump that discharges fluid at a flow rate depending on the vehicle speed, and operates when the discharge flow rate of the pump is equal to or higher than a predetermined value to operate a wheel braking device. a cylinder having an inlet for the discharged fluid and an outlet for the fluid at the other end; and a cylinder slidably fitted into the cylinder and partitioning the inside of the cylinder into a cylinder chamber on the inlet side and a cylinder chamber on the outlet side. and an orifice for communicating the two cylinder chambers, and an orifice opening/closing means for at least partially closing the orifice when braking is applied and opening the orifice when the brake is released. Characteristic cylinder device.