JPS6246053A - Backward speed control device for vehicle - Google Patents

Abstract

PURPOSE:To control the backward speed by operating a cut-off valve by a discharged fluid of the second pump when the backward speed is increased, thereby to intercept a discharge conduit, so that a piston is moved by a discharged fluid of the first pump. CONSTITUTION:When the discharged flow rate of the second pump 20 exceeds a designated quantity regulated by an orifice 29 with an increase in backward car velocity, a discharge conduit 12 is intercepted. A piston 10 is moved by oil in a cylinder chamber 11 to brake wheels through a brake master cylinder 17. Thus, a car can be automatically braked out to reach a fixed car velocity at the time of backward operation.

Description

[Detailed description of the invention] To Naoji 5 J22q22000'j-zu'IJ: The present invention is a vehicle such as a car or a tricycle, and the vehicle speed does not exceed a certain speed when going backwards. J. This relates to a reverse speed control device that automatically brakes the vehicle.

In vehicles equipped with reversing devices such as U-marukoma cars or tricycles, the driver turns his head toward the rear and checks what is behind him when reversing, so if the reversing speed is fast &J The faster the speed is, the greater the burden on the driver is, and considering the ease of driving when reversing, it is desirable to prevent the reversing speed from rising above a certain value.

For this reason, a conventional tricycle with a reverse mechanism has been developed which is equipped with a vehicle speed limiting device that is activated by detecting a reverse operation, and which limits the reverse speed to a predetermined value or less. 15! No. 1545 proposed by JP. ” The vehicle speed limiter has a vehicle speed detection circuit that detects medium speed, a reverse detection circuit that detects reverse operation,
Consisting of a discrimination circuit that discriminates the signals from both detection circuits and generates an output signal at a predetermined vehicle speed or higher during reverse, and an ignition stop circuit that stops the operation of the engine's ignition device based on the output signal from the discrimination circuit. and below the specified vehicle speed when reversing.”]
When the engine misfires, even if you turn the accelerator grip attached to the bar handle, the vehicle speed will be limited to a predetermined vehicle speed or less.

In addition, the inventors of the present invention set up electronic circuits in each building as in the conventional device, and instead of controlling the engine etc. through the circuits from these circuits to limit the vehicle speed. In order to more directly and effectively limit the vehicle speed to a predetermined value IJ,1'-, the predetermined flow rate is adjusted in one direction or the opposite direction in response to the vehicle speed as the vehicle moves forward or backward. 1′? Japanese Patent Application No. 59-234168 discloses a vehicle speed control device in which a pump is installed to discharge fluid at the pump, and a wheel braking device is actuated by the fluid discharged from the pump.
? I'm making plans. In this vehicle speed control device, the fluid discharged from the pump is guided through the brake conduit to the cylinder system, and from the cylinder system it is further returned to the oil tank through the initial conduit. The orifice restricts and restricts the flow rate flowing back into the oil tank. 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, so the force that operates the piston (A) is not generated in the cylinder device. However, when the vehicle speed increases above a certain value and the discharge flow rate of the pump exceeds the limited flow rate defined by the orifice, the pressure within the cylinder device N increases and moves the piston.

Then, the movement of this piston activates the wheel ff1ll motion device, which limits the vehicle speed to below a certain vehicle speed.

However, in this vehicle speed control system, when the wheel braking system operates as described above, the vehicle speed decreases and the pump discharge flow rate decreases accordingly, so screws 1 to 1 are no longer needed. Return to any position and the brake will be released.

However, at this time, since the fluid remaining in the cylinder is discharged through the orifice to the discharge conduit, rapid discharge cannot be expected, and the return movement of the screws 1 to 1 must be slow. As a result, the braking force maintains a high value for a relatively long time after the vehicle speed begins to decrease, as shown by the broken line a in FIG. 3, and fluctuates relatively significantly at medium speeds, as shown by the solid line. In Fig. 3, the horizontal axis represents the clearance, and the vertical axis represents the braking force or vehicle speed. Ideally, it is desirable that the vehicle speed be maintained at a constant speed below the predetermined value, as shown by the dashed line C, and for this purpose, the braking force must be reduced to the brake applied reverse speed, as shown by the dotted line d. desired.

Therefore, the present invention aims to provide a reverse speed control device that can obtain the braking operations described in c and d above.

For the sake of the Oumafuchi-Ken JUL” υL [written by L] For this reason,
In the present invention, first and second pumps each discharge fluid at a flow rate corresponding to the vehicle speed when the vehicle moves backward, a cylinder, a piston interlocked with a wheel braking device, and a cylinder chamber communicating with the first pump. a cylinder device having a cylinder device, an outlet conduit 11 connected to the cylinder chamber, and a cylinder device inserted into the discharge conduit, operated by the discharge fluid of the second pump, and when the flow 111 of the discharge fluid exceeds a predetermined value. and an orifice bypass connected to the outlet conduit across the isolation valve arrangement.

-4 According to the present invention, when the vehicle speed is below the predetermined value Js during reverse, the discharge fluid sent from the first pump to the cylinder chamber of the cylinder device is discharged from the open shutoff valve device and the orifice side. Since the gas is directly discharged through the discharge conduit, no substantial pressure is generated in the cylinder chamber, and the piston operates.

As the reverse speed increases, the discharge flow m of the first and second pumps increases.
When the flow rate increases and reaches a predetermined flow rate, the shutoff valve device is actuated by the discharge fluid from the second pump to shut off the discharge conduit, so that the discharge fluid that has flowed into the cylinder chamber from the first pump flows into the A refill. U1 is exited only through a side road,
When the discharge flow rate of the pump exceeds the flow rate defined by the orifice, the discharge fluid that accumulates in the cylinder chamber moves the piston and activates the wheel braking system.

When the wheels are braked in this way, the vehicle speed decreases, and the discharge flow rate of the pump also decreases, the piston begins to return to the position 4), but at this time, due to the decrease in the discharge flow rate of the second pump, the cutoff valve The device is activated and opens the discharge conduit again. Therefore, the flow m of the fluid discharged from the cylinder chamber increases by 4Jl, so that the residual pressure in the cylinder chamber rapidly decreases, and the screws 1 to 1 quickly return to their normal positions. In other words, the braking force is quickly released after the braking is applied, and smooth vehicle speed control a+ operation is achieved.

History] L measurement The present invention will be explained below with reference to the illustrated embodiments. FIG. 1 is a schematic view of the entire reverse speed control 6TI device to which the present invention is applied, but the illustration of the parts related to the second pump and shutoff device is omitted. First of all, in this Figure 1, the parts excluding the part between the second pump and the connecting valve system are shown.
An overview of this device will be explained. Reference numeral 1 denotes a vehicle speed take-out shaft connected to, for example, the engine's 1-transmission engine section, and rotates at a rotational speed that corresponds to the rotational speed of the final drive system of the vehicle and thus the vehicle speed. The medium speed extraction shaft 1 is connected to a pump drive shaft 3 via a one-way clutch 2, and the pump drive shaft 3 is connected to the rotor of a first pump 4. The one-way clutch 2 is released when the vehicle speed output shaft 1 rotates in the forward direction to cut off rotation transmission, and is engaged when the vehicle speed output shaft 1 rotates in the reverse direction to transfer the rotation of the vehicle speed output shaft 1 to the pump drive shaft. 3 to the first pump 4. Therefore, the first pump 4 operates only when the vehicle is moving backward. The vehicle speed output shaft 1 is not limited to the transmission section of the engine, but may be connected to an appropriate rotating section in the final drive system from the transmission section to the wheels, such as a differential gear unit.

The first pump 4 is a rotary pump such as a locoid pump or a gear pump, and when the rotor is rotated by the pump drive shaft 3, it sucks oil from the reservoir tank 5 through the suction pipe 6, and supplies it to the discharge pipe 7. Exhale. The discharge flow ω varies depending on the rotation speed of the pump drive shaft 3 and therefore the vehicle speed, and increases as the vehicle speed increases, but the rate of increase in the discharge flow rate with respect to the increase in vehicle speed may be constant, or may gradually increase or decrease. You can do it like this. The discharge pipe 7 is connected to a cylinder device 8.

The cylinder device 8 is a single-acting type, and includes a cylinder 9 and a piston 1.
0 and a cylinder chamber 11, and the II outlet pipe 7
is open to the cylinder chamber 11. The cylinder chamber 11 is also connected to the reservoir tank 5 via a discharge conduit 12, and at which connection part of the JJI outlet conduit 12 and cylinder chamber 11 a cutoff valve device 13 and an A refill side passage 14, which will be described later, are installed (). It is being

The oil discharged from the first pump 4 is sent into the cylinder chamber 11 via the discharge pipe 7, and is returned to the reservoir tank 5 through the A-refice side passage 14° + Jl outlet conduit conduit 12 (with the shutoff valve device 13 closed). ). As the reverse speed increases, the discharge flow rate from the first pump 4 increases to A of the orifice side passage 14.
If the original product exceeds the limit specified by Ref.15,
Due to the pressure of the oil accumulated in the cylinder chamber 11, the screw 1
~n 10 moves. Screws 1 to 10 are screws 1 to f1.
10a is connected to the piston 17a of the pre-m-1 mask cylinder 17 via the lever 16, and
0 moves to the left, the piston 17a is pushed into the brake mask cylinder 17, and the brake 4-
Hydraulic pressure is generated in the mask cylinder 17, and the hydraulic pressure is sent through the play pipe 18 to a brake member (not shown), such as a brake caliper, provided on the wheel, thereby braking the wheel. Note that in this embodiment, the piston 10
It is also linked to an operating member such as the brake pedal 19, and constitutes a part of a normal brake operating member.

Figure 2 shows the above cylinder assembly @8. A first pump 4° shutoff valve device 13 and a second pump 20 not shown in FIG.
FIG. The rotor 4a of the first pump 4 is connected to the pump drive shaft 3 as described above, and the rotor 4a of the second pump 20 is connected to the pump drive shaft 3.
0a is also connected.

That is, the first pump 4 and the second pump 20 are connected in series by a common drive shaft 3 and housed in a common casing 21. Suction ports 4b and 20 of each pump 4 and 20
b is connected to the reservoir tank 5 through the suction pipe 6, and the discharge port 4C of the first pump 4 is connected to the discharge pipe 7 as described above.
It communicates with the cylinder chamber 11 of the cylinder device 8 through the cylinder chamber 11 of the cylinder device 8. The piston 10 of the cylinder device 8 is biased to the right by a spring 22. The cylinder chamber 11 also communicates with a discharge line 12 leading to the reservoir tank 5, into which a shutoff valve arrangement 13 is inserted.

The shutoff valve device 13 consists of a cylinder 23 and a screw 24 slidably mounted inside the cylinder 23.
The screws 1 to 24 are urged rightward in the figure by a spring 25, and a cylinder chamber 2G is formed on the right side of the screws 1 to 24. An annular groove 27 is provided on the outer peripheral surface of each of the screws 1 to 24.
When screws 1 to 24 are in the right position J as shown in the diagram,
In alignment with the exhaust conduit 12, the exhaust conduit 12 is opened.

The cylinder chamber 26 communicates with the discharge 112 (LC) of the second pump 20 via a discharge pipe 28, and the orifice 2
The IJI outlet conduit conduit 12 is connected via the IJI outlet conduit 9.

After 11tl of the shutoff valve device 13 of the discharge conduit 12, the shutoff valve device 13 is connected by an orifice channel 14 into which the orifice 1 is connected.
5 is set c1 and C.

The screws 10 of the cylinder device 48 and the connecting valve device 13
Normally, the bismine 24 is pushed by the springs 22 and 25 and occupies the right position shown in the figure. When the reverse vehicle speed is low, the first pump 4 and the second pump 2
When the discharge flow 1B from 0 is small, it is connected to the cylinder chamber 26 of ζ 113 from the second pump 20 via the discharge pipe 28.
The oil fed into the cylinder chamber 26 passes through the orifice 29 and is directly discharged into the discharge pipe 12.
No pressure is generated within the piston 24, and the piston 24 is stopped in the right position. The oil fed into the cylinder chamber 11 of the cylinder device 8 via the discharge pipe 7 from the first pump 1'/I is also fed to the reciprocal conduit opened through the groove 27 of the doors 1 to 24 of the shutoff valve device 13. 12 and the orifice side passage 14 to the 1f tank 5, so no pressure is generated in the cylinder chamber 11, and the piston 10 also stops at the right position. There is.

As the reverse vehicle speed increases, the discharge flow rate of the first pump 4 and the second pump 20 also increases, but when the discharge flow rate of the second pump 20 exceeds a predetermined flow rate defined by the orifice 29, the flow rate inside the cylinder chamber 26 increases. The accumulated oil causes piston 24 to compress spring 25 and move to the left, blocking drain conduit 12. Then, the oil sent from the first pump 4 to the cylinder chamber 11 of the cylinder device 8 via the discharge pipe 7 is discharged only through the A refill side passage 14. When the discharge flow rate of 4 exceeds the predetermined flow rate defined by the orifice 15,
Alternatively, if the predetermined flow rate has already been reached when the screws 1 to 24 shut off the 1jl outlet pipe 12, the screws 1 to 10 will immediately resist the spring 22 due to the oil accumulated in the cylinder chamber 11, causing the screws 1 to 10 to move in the τ) direction. The middle wheel is braked via the brake master cylinder 17 described above.

In this way, the C wheel is braked and the vehicle speed decreases.
Along with this, the discharge flow rate of the pumps 4 and 20 also decreases,
When the discharge flow rate of the first pump 4 reaches the specified flow IJsuF by the A-refit 15, the flow between the outflow from the cylinder chamber 11 becomes the inflow flow ff1J: more than 4, so the screw 10 returns to its original position. Shilf+Meru. At this time, the discharge flow rate of the second pump 20 also becomes less than the specified flow rate by the A-refit 29, and the screw 1-24 similarly returns to the right position as shown in the figure, opening the discharge conduit 12. Therefore, since the flow rate of oil discharged from the cylinder chamber 11 increases, the remaining Ti in the cylinder chamber 11 rapidly decreases, the screw 1 hem 10 quickly returns to the right position, and the braking force is quickly released. It will be done. Note that by appropriately selecting the characteristics of the pumps 4, 20 and the A-refrigerator 15, 29, desired reverse speed control characteristics can be obtained.

11 Reverse Drifting 1 As described above, the reverse speed control device of the present invention has a first controller that discharges fluid at a flow rate corresponding to the vehicle speed when the vehicle is traveling backward.
and a second pump, a cylinder, a cylinder device having a cylinder chamber connected to the first pump and the first pump, and a cylinder chamber connected to the cylinder chamber, and an outlet conduit connected to the cylinder chamber. an IM valve device inserted into the second pump, operated by the fluid discharged from the second pump, and shuts off the discharge conduit when the flow rate of the discharged fluid exceeds a predetermined value; and the shutoff valve device. The above υ
Since the system consists of an orifice side passage connected to an exit pipe, the vehicle speed is automatically braked to prevent the vehicle speed from exceeding a certain speed when reversing, and the braking force is quickly released. , smooth vehicle speed control operation is 3 degrees.

[Brief explanation of drawings]

Fig. 1 shows an overview of the reverse speed control device F+ according to the present invention, and Fig. 2 shows the main parts of the device in more detail. There is a diagram to explain the braking force and the opening between n and '1 at medium speed. 1... Medium speed extraction shaft, 2... One-L clutch, 3
...Pump drive 111! , 4... first pump, 5...
... Reservoir tank, 6... Suction pipe, 7... Discharge pipe, 8... Cylinder device, 9... Cylinder, 10...
・Bis 1~n, 11...Cylinder device t, 12...
ill) υ pipe, 13...connection...i valve device, 14...
Olinois side road, 15...Olinois, 1G...
1 collar 117...B 1 Noki master cylinder, 18
...Brake piping, 19...B1 Noki pedal, 2
0...Second pump, 21...Casing, 22...
・Spring, 23...Cylinder, 24...Piston, 25...Spring, 26...Cylinder chamber, 2
7...ffl'i, 2B...discharge pipe, 2ri...A
- Reifuis. Daitanukito Burialist γ Ko Hara Bogai 2 people Figure 1

Claims (1)

[Claims] first and second pumps that discharge fluid at a flow rate corresponding to the vehicle speed when the vehicle moves backward; a cylinder device that has a cylinder, a piston that is interlocked with a wheel braking device, and a cylinder chamber that communicates with the first pump; a discharge conduit connected to the cylinder chamber; and a discharge conduit inserted into the discharge conduit, operated by the discharge fluid of the second pump, and shut off the discharge conduit when the flow rate of the discharge fluid exceeds a predetermined value. A vehicle reverse speed control device comprising: a shutoff valve device; and an orifice bypass connected to the discharge conduit across the shutoff valve device.