JPS62218243A - Backward speed controller for vehicle - Google Patents

Abstract

PURPOSE:To avoid getting any influence due to a variation in the promotion of deceleration by an automatic transmission as well as to restrict a backward speed without fail, by controlling an engine speed so as to cause a rotating speed of the control shaft, set up downward from an output shaft of the automatic transmission, to become less than the specified value. CONSTITUTION:In this saddle type four-wheeled vehicle 1, output of its engine 10 is transmitted to rear wheels 4 via an automatic transmission 15, a forward- backward selector device 20 and a drive chain 23c. And, at the time of backward motion, if a selector lever 20d is tilted to the R side, an engaging claw 20c is engaged with a backward gear group 20b, so that rotation of the engine 10 is transmitted to these rear wheels 4 via this gear group 20b. At this time, a backward position of the selector lever 20d is detected by a detector 22, and this detection signal is outputted to a solenoid 21g, making a cam plate 21c move to a full line position. With this constitution, a rolling weight 21d is moved outward in a radial direction with a rise in the rotating speed of a control shaft 21a, while a cam plate 21b is moved, rotating a governor 21e, and a throttle valve is turned round in the closing direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for regulating the backward speed of a vehicle equipped with an automatic transmission and a forward/reverse switching device to a predetermined speed or less. Book! Since the device is most suitable for, for example, a straddle-type vehicle for traveling on rough terrain equipped with wide ultra-low-pressure tires, the explanation will be given below mainly using a straddle-type four-wheel vehicle for traveling on rough terrain as an example.

[Conventional technology]

In general, a straddle-type vehicle for traveling on rough terrain is equipped with a gear type transmission to appropriately reduce the engine speed, and is also equipped with a forward/reverse switching device so that it can also go backwards. In such a vehicle, in order to facilitate driving operations when reversing, it is desirable that the vehicle speed not increase too much even when the occupant greatly operates the throttle grip.

In order to meet the above requirements, conventionally, there are vehicles equipped with a vehicle speed limiting device that limits the engine rotational speed to a predetermined value or less when the reverse switching device is detected (for example, Japanese Patent Laid-Open No. 59
(Refer to Publication No.-155545).

Incidentally, the above-mentioned vehicle for traveling on rough terrain is required to be easier to drive due to its intended use.

To this end, it is desirable to provide an automatic transmission that automatically changes the reduction ratio according to the engine rotation speed and running resistance, thereby eliminating the need for a gear change operation, since this allows the driver to concentrate on steering operations and the like. On the other hand, even in vehicles equipped with this automatic transmission, it is desirable to limit the reverse speed to a predetermined speed or less, similar to the vehicle described in the above publication.To do this, when reverse travel is detected, if the speed exceeds the predetermined speed, the engine ignites. It is conceivable to reduce the vehicle speed when reversing by cutting the

[Problem that the invention seeks to solve]

However, when suppressing this reverse speed, even if the reverse speed limiting device for a vehicle with a gear transmission described in the above-mentioned publication is directly applied to a vehicle with an automatic transmission, the reverse speed cannot be limited to a predetermined speed or less. In other words, in an automatic transmission, the reduction ratio automatically changes depending on the engine speed and running resistance, so even if the engine speed is controlled to a predetermined value, for example, when driving on sandy terrain with high running resistance or on small pavement. When traveling on a road, the vehicle speed is higher than when running resistance is small, and in the end, simply controlling the engine speed to a predetermined speed does not reliably limit the vehicle speed to the predetermined speed.

In addition, in the method of cutting off ignition to the engine, the engine is used in a low rotational speed range, that is, in a low output state, so there is a problem that the output is likely to be insufficient when going backwards up a steep slope.

Therefore, an object of the present invention is to provide a vehicle with an automatic transmission.
It is an object of the present invention to provide a reverse speed control device that can reliably limit the reverse speed to a predetermined value or less and that can use the high output range of the engine.

[Means for solving problems]

The present invention relates to a vehicle equipped with an automatic transmission and a forward/reverse switching device, including a backward movement detection means, and an output shaft of the automatic transmission when the detection means detects a backward movement.

It is characterized by comprising an engine rotation control means for detecting the rotation speed of either the drive wheel shaft or another rotating shaft between the two axles, and controlling the engine rotation speed so that the detected speed is equal to or less than a predetermined value. There is.

[Effect]

In the vehicle reverse speed control device according to the present invention, the engine speed is controlled so that the rotational speed of the rotating shaft after the automatic transmission is below a predetermined value, so that the reduction ratio is automatically adjusted by the automatic transmission. If the speed change occurs, the engine speed will be controlled according to the change in the reduction ratio, which means that the influence of the change in the reduction ratio caused by the automatic transmission can be avoided.
The reverse speed can be reliably controlled to a predetermined value or less. Furthermore, if the running resistance is large, the engine speed can be increased accordingly, so the engine is used in a high output range, and there is no shortage of output even on steep slopes.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 3 are diagrams for explaining a reverse speed control device for a straddle-type four-wheeled vehicle according to an embodiment of the present invention. In the figure, ■ is a straddle-type four-wheeled vehicle for irregular running to which this embodiment is applied, and the front and rear portions of the body frame 2 of the four-wheeled vehicle 1 are located on the left side, respectively.

A pair of right-hand front wheels 38 and rear wheels 4 with wide ultra-low-pressure tires are installed, and a front fender 5 is mounted above each of these wheels 3.4.
．． A rear fender 6 is provided.

Furthermore, on the top of the vehicle body frame 2, from the front, a steering handle 7, a fuel tank 8. and a saddle-shaped seat 9 are attached.

An engine 10 is installed approximately in the middle of the vehicle body frame 2.
is installed. A piston valve type carburetor 11 that adjusts the flow rate of combustion air by moving a piston valve up and down is connected to the engine IO, and the piston valve of the carburetor 11 is connected to the throttle grip 7 of the steering handle 7.
It moves up and down by rotating a. An air cleaner 12 is connected to the carburetor 11 via a supply duct 12a, and a butterfly valve type throttle valve 13 for adjusting the air flow rate is rotatably disposed in the supply duct 12a.

A belt-type automatic transmission 15 is housed in a belt case 14 that also serves as the crankcase of the engine 10. This automatic transmission 15 has a drive side boot IJ attached to a crankshaft 10a which is a drive shaft.
16, a driven pulley 17 attached to the driven shaft 17b, and a V-belt 18 wound between both pulleys 16 and 17.
It is composed of. The automatic transmission 15 automatically changes the reduction ratio so that the higher the engine speed and the lower the running resistance, the smaller the reduction ratio, and vice versa. It is configured to change so that

Further, a gear box 1 is provided on the side of the belt case 14.
A forward/reverse switching device 20 is housed in the box 19. The switching device 20 is mainly a forward gear group 20a.

Reverse gear group 20b, engaging claw 20C6 slidably mounted on the driven shaft 17b in the axial direction; cam member 2Of that slides the retaining claw 20C; and switching lever 20 that rotates the engaging claw 20C.
It is composed of d. Further, a drive chain is installed between the drive sprocket 23a attached to the output shaft 20e of the switching device 20 and the driven sprocket 23b attached to the rear axle 4a directly connecting the left and right rear wheels 4. 23
C is wound.

The reverse gear group 20b of the switching device 20 includes:
Although not shown, an idle gear is meshed with the vehicle speed control shaft 21a, which is a support shaft for this idle gear.
A governor 2 for controlling the rotational speed of the engine 10 so that the control shaft 21a and therefore the reverse vehicle speed are below a predetermined value.
1 is attached (see Figure 3). This governor 21 includes a pair of cam plates 21b and 21C on the control shaft 21a.
It rotates together with the control shaft 21a and is mounted so as to be slidable in the axial direction, and a spherical transfer way 21d is disposed between the cam plates 21b and 21C. A swingable governor lever 21e and a switching lever 21f are in contact with the axial outer surfaces of the cam plates 21b and 21c, and the governor lever 218 and the cam plate 21b
is biased to the left in the figure by a spring 21h. Further, a solenoid 21g is connected to the switching lever 21f.

And the solenoid 21g of the governor 21 has the above-mentioned
A reverse position detector 22 is connected to detect when the switching lever 20d of the reverse switching device 20 is operated to the reverse position. This solenoid 21g is the reverse position detector 22.
When the detection signal from the switch is input manually, the switching lever 21f is swung to the position shown by the solid line in FIG. Further, the governor lever 21e is linked and connected to the throttle valve 13.

Next, the effects of this embodiment will be explained.

In the saddle type four-wheel vehicle 1 of this embodiment, the output of the engine 10 is controlled by the automatic transmission 15. It is transmitted to the rear wheels 4 via the forward/reverse switching device 20 and the drive chain 23c. in this case,
In the automatic transmission 15, the higher the engine speed, the more
Furthermore, the smaller the running resistance, the larger the diameter of the windings on the driving pulley 16 and the smaller the diameter of the windings on the driven pulley 17. In other words, the reduction ratio becomes smaller, and as a result, the vehicle speed becomes faster. On the other hand, the lower the engine speed and the greater the running resistance, the diameter of the winding of each pulley will be opposite to that in the above case, and the vehicle speed will be slower.

In the case of forward movement, the switching lever 20d is swung to the forward position "F" in FIG. Then, the engaging pawl 20c engages with the forward gear group 20a, and the engine rotation is caused by this gear group 2.
The signal is transmitted to the rear wheels through 0a, causing the vehicle to move forward. At this time, since the reverse position detection signal is not input to the solenoid valve 21g, the switching lever 21f is rotated to the position indicated by the two-dot chain line in the figure, and the cam plate 21c is therefore located at the right end in the figure. As a result, transfer weight 2
1d moves outward in the radial direction, the cam plate 21b remains at its right end position and does not move to the left in the axial direction. As a result, the throttle valve 13 is kept fully open and the engine rotation is normal. It is controlled according to the throttle operation, that is, by the vertical movement of the piston pulp of the carburetor 11.

In the case of reversing, the switching lever 20d can be tilted to the "R" side, thereby causing the engaging pawl 20c to move to the reverse gear group 2.
0b, the rotation of the engine IO is transmitted to the rear wheels 4 via this reverse gear group 20b, and the vehicle travels backward. At this time, the reverse position detector 22 detects the reverse position of the switching lever 20d and outputs a detection signal to the solenoid 21g.

Then, the cam plate 21C is moved to the position indicated by the solid line in the figure by the solenoid 21g. Therefore, when the rotational speed of the control shaft 21a increases, that is, when the reverse speed of the vehicle increases, the transfer weight 21d moves outward in the radial direction, which causes the cam plate 21b to move to the left in the figure, and the governor lever 21
By rotating e clockwise, the throttle valve I3 is rotated in the closing direction. As a result, the combustion air flow rate to the engine 10 is not determined by the vertical movement of the piston valve of the carburetor 11, but by the throttle valve 13.
The upper limit is regulated by the degree of opening.

As a result, even if the occupant greatly rotates the throttle grip, the rotational speed of the control shaft 21a is controlled to be below the predetermined rotational speed, and the reverse speed of the vehicle is controlled to be below the predetermined speed.

In this way, in the saddle type four-wheel vehicle 1 of the present embodiment, the engine rotation speed is controlled so that the rotation speed of the control shaft 21a disposed after the output shaft of the automatic transmission 15 is below a predetermined value. Therefore, it is possible to eliminate the influence caused by the automatic change in the reduction ratio of the automatic transmission I5, and it is possible to reliably limit the reverse speed to a predetermined value or less in a vehicle equipped with the automatic transmission.

In addition, when running resistance increases, for example when climbing a steep slope by reversing, the throttle valve 13 is controlled to keep the engine speed high until the predetermined vehicle speed is reached. Engine power is obtained and there is no shortage of power.

In the above embodiment, the rotational speed of the control shaft 21a is controlled to be below a predetermined speed, but in the present invention, the controlled object does not necessarily have to be the control shaft 21a, but is essentially the output of the automatic transmission. Any rotational axis after the shaft may be used, for example, the rotational speed of the axle 4a may be controlled.
Further, the control means is of course not limited to a mechanical type, and may be an electric type.Furthermore, in the above embodiment, the case where the automatic transmission is a V-belt type continuously variable transmission has been explained. The present invention is not limited to V-belt type continuously variable transmissions, but can be applied to any automatic transmission as long as the reduction ratio automatically changes according to engine speed and running resistance.

〔Effect of the invention〕

As described above, according to the vehicle reverse speed control device according to the present invention, the engine rotation speed is controlled so that the rotation speed of the rotating shaft after the automatic transmission is equal to or less than a predetermined value. This has the effect of reliably limiting the reverse speed to a predetermined value or less by avoiding the influence of changes in the reduction ratio due to

[Brief explanation of drawings]

1 to 3 are for explaining a reverse speed control device according to an embodiment of the present invention. FIG. 1 is a side view of a straddle-type four-wheel vehicle to which the device of this embodiment is applied FIG. 2 is a plan view thereof, and FIG. 3 is a cross-sectional side view of the governor portion. In the figure, l is a straddle-type four-wheel vehicle, 10 is an engine, and 15
2 is an automatic transmission, 20 is a forward/reverse switching device, 21 is a governor (engine rotation control means), 21a is a vehicle speed control shaft (rotation shaft), and 22 is a reverse position detector (reverse motion detection means). Patent Applicant: Yamaha Motor Co., Ltd. Figure 3 Handwritten by: Author (Sponsored) May 22, 1986

Claims (1)

[Claims] (1) In a vehicle equipped with an automatic transmission device that automatically changes the reduction ratio depending on the engine speed and running resistance, and a forward/reverse switching device, a reversing detection means for detecting a reverse switching operation by the forward/reverse switching device; , when the backward movement detecting means detects the backward movement, the output shaft of the automatic transmission, the driving wheel shaft,
detecting the rotational speed of any of the other rotational axes between the two axes;
A reverse speed control device for a vehicle, comprising: engine rotation control means for controlling the engine rotation speed so that the detected rotation speed is equal to or less than a predetermined speed.