JPS62152923A - Switch-back control system for industrial vehicle - Google Patents

Abstract

PURPOSE:To improve the working efficiency by judging the loading state or not and carrying out switch back speedily in the vacant loaded sate and carrying out switch back with little shock in the loaded state, in an industrial vehicle equipped with an automatic transmission using a clutch. CONSTITUTION:In an industrial vehicle equipped with an automatic transmission using clutch, e.g., a fork lift, a loading detector 1 detects the loaded state. A loading state judging part 2 judges the loaded state or not from the existence of the signal supplied from the loading detector 1. The switch-back starting speed which is different according to the loaded state or not is set in a car speed setting part 3 according to the signal supplied from the loading judging part 2. Further, the car speed set in a car speed setting part 3 and the car speed at present are compared in a car speed comparison part 4, and when the car sped at present becomes smaller, a signal is outputted. Then, selection is carried out in a first - second speed selecting part 5 and an advance/retreat selecting part 6, by the signal supplied from the car speed comparison part 4.

Description

[Detailed Description of the Invention] [Summary] In an industrial vehicle equipped with an automatic transmission using a clutch, the speed at which switchback starts is controlled depending on whether it is in an empty state or a loaded state. This makes it possible to switch back quickly when empty and while ensuring the safety of the cargo when loaded.

C. Industrial Application Field] The present invention relates to a switch bank control system for an industrial vehicle having an automatic transmission using a clutch.

Recently, automobiles have been developed that use a normal clutch and perform automatic gear shifting under microprocessor control, and from the user's perspective, they exhibit the same automatic gear shifting performance as a torque converter type automatic transmission, and have high driving power transmission efficiency. It has been commercialized.

The present invention relates to a switchback control system for industrial vehicles, particularly forklifts, equipped with automatic transmissions using this clutch.

[Prior Art] Conventionally, in a forklift truck equipped with an automatic transmission using a clutch, switch bank control is started at the same speed whether the truck is empty or loaded. .

[Problem to be solved by the invention] In order to speed up loading operations, a forklift truck is only required to switch back as quickly as possible when it is empty, but when it is loaded, it is necessary to switch back as quickly as possible. Considering this, switchbacks should be performed with as little shock as possible.

If the switch bank is operated at the same speed as when the load is loaded, the shock will be large and the safety of the load will be compromised.

The present invention aims to provide a switchback control system for industrial vehicles that solves these problems.

[Means for Solving the Problems] FIG. 1 shows a block diagram of the principle of a switchback control system for an industrial vehicle according to the present invention.

In FIG. 1, ``■'' is a loading detector provided on the loading platform to detect the loading state.

Reference numeral 2 denotes a loading determination unit that determines whether the vehicle is in an empty state or a loaded state based on the presence or absence of a detection signal from the loading detector 1.

Reference numeral 3 denotes a vehicle speed setting section that sets a switch bank start speed that differs depending on whether the vehicle is in an empty state or a loaded state, based on a judgment signal from the loading judgment section 2.

Reference numeral 4 denotes a vehicle speed comparison section that compares the speed set by the vehicle speed setting section 3 and the current speed of the vehicle, and outputs a signal when the latter speed is smaller.

Reference numeral 5 denotes a 1st-2nd speed switching section that performs downshift control based on the output signal of the vehicle speed comparison section 4.

Reference numeral 6 denotes a forward/reverse switching section that generates a control signal for switching between forward/reverse travel.

[Function] With the above configuration, it is possible to detect whether the vehicle is loaded or not, and perform switchback quickly when the vehicle is unladen, and with less shock when it is loaded, taking into account the safety of the cargo. It becomes possible to control the

[Example] The present invention will be described in more detail below with reference to Examples shown in FIGS. 2 and 3.

FIG. 2 is a system configuration diagram of an industrial vehicle that uses a clutch and performs automatic gear shifting under microprocessor control.

In FIG. 2, ECU is an electronic control unit,
The system is controlled by a microprocessor.

The power generated by the engine is transmitted to the transmission via the clutch, where 1st-2nd gear switching and forward/reverse gear switching are performed, and the power is transmitted to the axle through the differential gear.

The electronic control unit (ECU) receives instruction input from the driver's accelerator pedal, brake pedal, and F-R switching lever, and controls the vehicle speed sensor, input shaft rotation speed sensor, engine rotation speed sensor, and F-R gear position. switch, 1-2 speed gear position switch,
and the feedback input from the clutch sensor, equivalent to manual gear shifting operation by the most experienced operator.
A throttle actuator, a thalassoia actuator, a 1-2 speed gear switching actuator, and an FR gear switching actuator are controlled by calculating a shift point at which acceleration/deceleration is performed smoothly without causing a shift shock.

Switchbacks are also controlled by the electronic control unit (ECU) as part of this automatic shift control, but in order to reduce the shock during switchbacks and to avoid putting strain on the transmission, the switchbank starting speed is kept constant. A darkness value is set, and control is performed to downshift and switch back when the value falls below this value.

This avoids the poor power transmission efficiency of a torque converter type automatic transmission, and provides a vehicle that has the same shift performance as a torque converter type automatic transmission.

In addition, the inching pedal is used in forklifts.
This pedal is mainly used to control vehicle speed during cargo handling operations.

FIG. 3 is a flowchart showing the processing steps of the embodiment of the present invention.

Next, the processing procedure will be explained according to each step of the flowchart shown in FIG.

■Start switchback control according to instructions from the F-R switching lever.

■Check whether or not the cargo is loaded by the signal from the loading detector■ Make a judgment, if Yes, go to the next step, if NO, ■ If so, move to step ω.

■Switch bank start speed SD: Set the set vehicle speed α when unloaded as SPD, and move to step ■.

■Switch bank starting speed SD: Set the set vehicle speed β during loading as SPD, and move to step ■.

■Compare the current actual vehicle speed SPD and the set vehicle speed 5DiSPD, and if SPD<SD: SPD, proceed to step (2), and if NO, return to step (2).

■Shift down to l speed and move to step ■.

■ Perform forward/forward switching control and move to step ■.

■End switch bank control.

[Effects of the Invention] As explained above, according to the present invention, it is possible to control the switch bank to be performed quickly when the vehicle is unloaded, and to perform the switch bank with less shock when the vehicle is loaded, taking into account the safety of the cargo. This makes it possible to obtain a vehicle with extremely high work efficiency, which has great practical effects.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the principle of the present invention, FIG. 2 is a system configuration diagram, and FIG. 3 is a flowchart of an embodiment of the present invention. In the drawings, 1 is a loading detector, 2 is a loading determination section, 3 is a vehicle speed setting section, 4 is a vehicle speed comparison section, 5 is a 1st-2nd speed switching section, and 6 is a forward/reverse switching section. strongζ now′: yam

Claims (1)

[Claims] In an industrial vehicle equipped with an automatic transmission using a clutch, there is provided a loading detector (1) for detecting a loaded state, and a loading detector (1) for determining whether the loaded state is an empty state or a loaded state. Loading judgment part (2)
and a vehicle speed setting unit (3) that sets different vehicle speeds depending on whether the vehicle is in an unloaded state or a loaded state, and is configured to change the speed at which switchback is started depending on the loaded state. Vehicle switchback control system.