JPH0534996Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial field of application> The present invention relates to a high-speed reversing check device for vehicles such as tractors, which throttles the engine fuel system when the transmission is at high speed and the forward/reverse switching device is in reverse. This suppresses engine rotation and reduces travel speed.

<Prior art and its problems> The traveling transmission system of a tractor incorporates a transmission device consisting of a main transmission section, an auxiliary transmission section, a creep transmission section, etc., and a combination of these transmission sections enables multi-speed shifting. It's getting old.

Conventionally, in this type of transmission system, the reverse gear has a larger reduction ratio than the forward gear and is usually incorporated into the main transmission section, so the maximum speed when traveling in reverse is lower than that when traveling forward. is common.

However, the traveling transmission system is equipped with a forward/reverse switching device,
With the advent of vehicles that allow you to easily switch between forward and reverse with a single forward/reverse switching lever, if you set the transmission to maximum forward speed and then set the forward/backward switching device to reverse, you can easily switch between forward and reverse. This resulted in a problem where the maximum speed when reversing was too high.

The present invention was provided for the purpose of solving such conventional problems.

<Means for Solving the Problems> The present invention is intended to reduce the engine rotation when the transmission is at high speed and the forward/reverse switching is reverse.
In a vehicle equipped with a transmission 11 capable of multi-speed shifting and a forward/reverse switching device 10, high speed detection switches 28, 2 for detecting the high speed of the transmission 11 are provided.
9, 30, and a reverse detection switch 19 for detecting backward movement of the forward/reverse switching device 10, and a fuel cut valve that throttles the fuel supply to the engine 7 when these detection switches 19, 28, 29, 30 are activated. 41 is interposed in the fuel supply path to the fuel injection pump 40.

<Function> When each transmission section 12, 13, 14 of the transmission 11 is set to high speed, the high speed detection switches 28, 2
9,30 works. Further, when the forward/reverse switching device 10 is set to reverse, the reverse detecting switch 19 is activated.
Therefore, the relay 50 operates and the deceleration solenoid 4
6 is activated, the fuel cut valve 41 goes from fully open to the throttle state, and the fuel supply to the fuel pump 40 is throttled, so the fuel supply to the engine 7 is throttled regardless of the opening degree of the throttle valve. Rotation decreases.

<Embodiment> Hereinafter, the present invention will be described in detail with reference to the illustrated embodiment. In FIG. 2, reference numeral 1 denotes a tractor body, which includes an engine, a transmission case 2, and the like. 3 is a hydraulic system, 4 is a rear wheel fender, and 5 is a driver's seat, which is provided on a floor cover 6 installed between the left and right rear wheel fenders 4.

The traveling transmission system 8 that transmits power from the engine 7 to the rear wheels is provided with a clutch 9, a forward/reverse switching device 10, a transmission 11, etc., as shown in FIG. It consists of a transmission section 12, an auxiliary transmission section 13, a creep transmission section 14, etc., and is capable of multi-stage shifting.

The forward/reverse switching device 10 is provided inside the mission case 2, and can be switched by a switching lever 16 pivotally supported on a support plate 15 via a rod 17, an operating shaft 18, etc. A reverse detection switch 19 detects the reverse state in conjunction with
is provided.

A transmission 11 is also provided in the transmission case 2, and its main transmission section 12 is operated by a main transmission lever 21 supported on a transmission platform 20 via an operating shaft 22, and the sub-transmission section 13 is pivoted by a support plate 15. The supported sub-shift lever 23 connects the link mechanism 24 and the operation shaft 25.
The creep transmission section 14 can be operated by a creep transmission lever 26 via an operating shaft 27, respectively. And each operation axis 2
2, 25, 27, each transmission section 12, 1
High speed detection switch 2 that detects high speeds of 3 and 14
8, 29, and 30 are provided. 31 is a step.

Figure 1 shows an electric circuit, 32 is a battery, 3
3 is a key switch, with on contact 34 and off contact 3
5. 36 is an alternator, 37 is a regulator, and 38 and 39 are relays that are energized and close their contacts when the alternator 36 is operated. 40 is a fuel injection pump that supplies fuel to the engine (diesel) 7, in which a fuel cut valve 41 is incorporated, and a rod 4 that operates the cut valve 41;
2 is connected to the actuation link 43. The operating link 43 is pivotally supported by a support shaft 44, and a stop solenoid 45 and a deceleration solenoid 46 are connected to the operating link 43.

The stop solenoid 45 is connected from the stop timer 47 to the off contact 35 of the key switch 33 via the contact of the relay 39, and after the key switch 33 is connected to the off contact 35, it is activated via the stop timer 47 for a certain period of time. It's summery.

Reference numeral 48 denotes a fuse box inserted into the ON contact 34 side of the key switch 33, to which a back clamp 49 is connected via the reverse detection switch 19, and in parallel with the back clamp 49, high speed detection switches 28, 29, 30 and a relay 50 are connected. A series circuit with is connected. The contact 51 of the relay 50 is
Fuse box 48 along with deceleration solenoid 46
It is connected to the.

As shown in FIG. 4, the fuel cut valve 41 has a spool 56 assembled in a main body 55, which has a port 52 connected to the oil feed pump, a port 53 connected to the fuel injection pump 40, and a return port 54. It consists of a lot of things. The spool 56 has two aperture parts 5
7 and 58, and is configured so that there is a throttle state in which the amount of fuel supplied to the engine 7 is reduced to about half between the open state and the closed state. Note that a fuel throttling means 59 is constituted by the deceleration solenoid 46, the cutoff valve 41, and the like.

In the above configuration, the tractor engine is set at maximum rotation during operation. In this state, if each transmission section 12, 13, 14 of the transmission 11 is set to high speed, the high speed detection switches 28, 29,
30 works. Then, when the forward/reverse switching device 10 is set to reverse and the vehicle attempts to enter reverse, the reverse detecting switch 19 is activated, a closed circuit including the ON contact 34 of the key switch 33 is formed, and the relay 50 is energized. Therefore, the contact 51 closes, the deceleration solenoid 46 operates, and pulls the spool 56 of the fuel cut-off valve 41 via the operating link 43 and the rod 42, so that the fuel cut-off valve 41 changes from the fully open state shown in FIG. 4A to the state shown in FIG. 4B. Since the vehicle enters a throttle state and the amount of fuel supplied to the engine 7 decreases, the engine speed decreases and the vehicle moves backward at a speed suitable for backward movement. At this time, the cross lamp 49 is also lit.

When the forward/reverse switching device 10 is set in the forward direction, the deceleration solenoid 46 is not activated and the cut valve 41 returns to the fully open position.

When the key switch 33 is put into the off contact 35 to apply the key stop, the stop solenoid 45 is energized and the cut valve 41 is closed as shown in FIG. 4C, so that the fuel stops and the engine stops.

Note that if the solenoid is of a two-stage operating type, it can also be configured with one solenoid.

In the case of this two-stage operation type, the stop solenoid 45 may be used as is and connected to the fuse box 48 through a contact 51 of a relay 50 in addition to the stop timer 47, as shown in FIG.

In this way, the relay 50 will work and the contact 5
1 closes, the stop solenoid 45 operates and throttles the fuel to a cut state, so the engine stops and the vehicle does not move backward at high speed.

Note that if the high-speed detection switches 28, 29, and 30 are installed using the existing back clamp 49 circuit, the configuration can be simplified and implemented at low cost.

<Effects of the invention> According to the invention, when the transmission is at high speed and the forward/reverse switching device is in reverse, the throttling means operates and throttles the fuel supply to the engine, so engine rotation is suppressed and it is possible to move backward at high speed. disappears.

Further, according to the present invention, since the fuel cut valve is provided in the fuel supply path separately from the fuel injection pump, the structure is simpler than that in which the throttle valve of the fuel injection pump is operated. That is, when operating the throttle of the fuel injection pump, the throttle is connected to the accelerator operation system, which makes the operation system complicated, but in the present invention,
Since the fuel is restricted by a fuel cut valve separate from the fuel injection pump, the structure is simplified.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing one embodiment of the present invention;
3 is an explanatory diagram of the transmission system, FIGS. 4A to 4C are sectional views of the fuel cut valve, and FIG. 5 is a circuit diagram showing another embodiment. 7...Engine, 8...Traveling transmission system, 10...
Forward/forward switching device, 11...Transmission device, 19...Reverse detection switch, 28-30...High speed detection switch, 41...Fuel cut valve, 46...Deceleration solenoid, 59...Fuel throttling means.

Claims (1)

[Scope of utility model registration request] The traveling transmission system 8 includes a transmission 11 capable of multi-speed shifting.
and a forward/reverse switching device 10, high speed detection switches 28, 29, 30 for detecting the high speed of the transmission 11, and a reverse detection switch 19 for detecting the backward movement of the forward/reverse switching device 10. These detection switches 19, 28, 2
A fuel cut valve 41 that throttles the fuel supply to the engine 7 when the fuel injection pump 40 is operated.
A high-speed reverse check device for a vehicle, characterized in that the device is interposed in a fuel supply path to the vehicle.