JP2005068935A - Throttle switch doubling as mode selecting switch for construction equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a throttle switch doubling as a mode selecting switch for construction equipment, which can save a space necessary for arrangement of the throttle switch and the mode selecting switch, and brings improved operability of the switches. <P>SOLUTION: The throttle switch for the construction equipment doubles as the mode selecting switch, and consists of a switch main body having mounted thereon the mode selecting switch and an electrical resistor, and a knob mounted on the main body via a shaft in a manner capable of rotating and pressing downward. The shaft has an electric armature attached thereto. Therefore when the knob is pressed, the mode selecting switch is changed over, which enables successive switching of selected modes whenever the knob is pressed. Further by rotating the knob, engine rotational speed can be increased/decreased. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a throttle switch for controlling the engine speed of a construction machine, and in particular, by setting an optimum engine speed and a discharge amount of a variable hydraulic pump in advance according to the work mode of the construction machine. This is also used as a work mode selection switch for selecting a certain work mode.

In general, a construction machine such as an excavator is equipped with an engine having a governor mechanism for controlling the number of rotations and a variable hydraulic pump driven by the engine. It is operating.
The governor mechanism is controlled by a throttle switch, and works according to various situations while adjusting the fuel injection amount to control the engine speed (for example, see Patent Document 1).

  In addition, there are various work modes for work of a construction machine such as an excavator. For example, since it can be divided into heavy excavation work, standard excavation work, light excavation work, etc., the modes are divided into heavy excavation mode (H), standard excavation mode (S), light excavation mode (L), etc. according to the work form. From the combination of the preset engine speed and the variable hydraulic pump discharge amount, the mode selection switch is used to select an optimal combination for the mode of the work to perform an effective work ( For example, see Patent Document 2).

Furthermore, it is also known that an automatic mode (A) is set in which a work mode as described above is set, a change in load is detected, and the work mode is automatically switched according to a change in work content. (For example, refer to Patent Document 3).
As described above, in the construction machine, according to the work, the work is performed by controlling the engine speed by the throttle switch, or the work mode set in advance by the mode selection switch is selected.

Japanese Patent Laid-Open No. 9-53479 (FIGS. 1, 2 and 2 to 3) Japanese Patent Publication No. 5-17387 (FIG. 1, pages 2 to 5) JP-A-8-93520 (FIGS. 1, 3, and 1 to 3)

In a conventional control mechanism that enables selection of a mode corresponding to a work mode, a mode selection switch separate from the throttle switch is provided.
For this reason, it takes a lot of space to install the throttle switch and the mode selection switch in the driver's cab, and both switches that are used in a similar manner may be arranged apart from each other in some cases. There was an inconvenience that the operability was inferior.
It is an object of the present invention to obtain a throttle switch that also serves as a mode selection switch of a construction machine that can save space in the arrangement of the throttle switch and the mode selection switch and can improve operability.

  A throttle switch that doubles as a mode selection switch for a construction machine, and is mounted on a switch body that is equipped with a mode selection switch and an electric resistor, and that is pivotable and pushable via a shaft. An electrical contact piece is attached and the mode selection switch is switched by pushing the knob. Each time the knob is pushed, the mode to be selected can be switched sequentially, and the engine speed can be increased or decreased by turning the knob. It was.

  In addition, a knob is attached to the switch main body to which the mode selection switch and the electric resistor are attached via a hollow shaft to which an electric contact piece is attached, and the shaft is slidably inserted in the axial direction of the hollow shaft, The mode selection switch is switched by pressing the shaft, and the mode to be selected can be sequentially switched each time the shaft is pressed, and the engine speed can be increased or decreased by rotating the knob.

  Furthermore, the modes that are switched by the push operation are the standard excavation mode, the heavy excavation mode, and the light excavation mode, and the modes that are switched sequentially by these push operations are the standard mode and the automatic mode. These modes are switched alternately, and the mode selection switch is a single-position stable switch that returns to its original position when the knob is not pressed, and the receiving seat is fixed to the shaft. And an urging means is provided between the receiving seat and the switch body, and the shaft returns to its original position when the knob is not pushed.

When the knob is not pressed, the normal throttle operation can be performed. By pressing the knob, the work mode can be switched, and the throttle switch is also used as a mode selection switch, saving the switch layout space. it can. In addition, the throttle switch and mode selection switch, which are used in a similar way, have been combined, improving the operability of the switch.
Furthermore, since the throttle can be operated even during the mode selection operation, the workability of the construction machine has expanded.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view of an engine control mechanism embodying the present invention, FIG. 2 is an external perspective view of the throttle switch of the present invention, FIG. 3 is a longitudinal sectional view thereof, and FIG. FIG. 5 is a longitudinal sectional view showing the above example, and FIG. 6 is an explanatory diagram showing a mode switching procedure.

In the figure, 1 is an engine, 2 is a variable hydraulic pump driven by the engine 1, and the work actuator of the construction machine is operated by the hydraulic pressure. A regulator 3 controls the discharge amount of the variable hydraulic pump 2.
A throttle motor 4 is attached to the engine 1 and operates a governor device (not shown) that adjusts the fuel injection amount to control the engine speed.

The throttle motor 4 and the regulator 3 are connected to a controller 5 and are actuated by a command signal from the controller 5.
A rotation sensor 6 is provided on the output shaft of the engine 1, and the number of rotations of the engine 1 is detected and input to the controller 5.
Reference numeral 7 denotes a throttle switch that also serves as a mode selection switch according to the present invention, which has a configuration that will be described later, and is connected to the controller 5.

Now, the configuration of the throttle switch 7 also serving as a mode selection switch will be described. Reference numeral 10 denotes a knob, and 11 denotes a shaft fixed to the knob 10 integrally. The knob 10 is mounted on the switch body 12 via the shaft 11 so as to be rotatable by a predetermined angle and capable of being pushed.
Reference numeral 13 denotes a receiving seat fixed to the lower end of the shaft 11, and a spring 14 as a biasing means is provided between the receiving seat 13 and the switch body 12, and the receiving seat 13 is always directed upward. Energized. Although the throttle switch 7 may be mounted sideways, for the sake of convenience of explanation, the illustrated posture is described as the vertical direction.

Reference numeral 15 denotes an electrical resistor attached to the switch body 12 side, and 16 denotes an electrical contact piece attached to the receiving seat 13.
The electrical contact piece 16 is rotated about the shaft 11 by turning the knob 10, and the phase of the electrical resistance is shifted by the positional relationship of the electrical contact piece 16 with respect to the electrical resistor 15 to increase or decrease the output. The

Reference numeral 17 denotes a mode selection switch attached to the bottom of the switch body 12, and the shaft 11 contacts the mode selection switch 17 when the knob 10 is pushed.
The mode selection switch 17 is, for example, a single-position stable type push button switch or micro switch in which the button or lever returns to its original position when the push operation is not performed. A switching signal is issued to switch the set mode sequentially.

As the work mode, a heavy excavation mode (H), a standard excavation mode (S), and a light excavation mode (L) are set.
In addition, when the work mode is automatically switched according to the change of the work content, the standard mode (M) and the automatic mode (A) are set, and the standard mode (M) and the automatic mode ( A) can be switched alternately.

Therefore, the operation signal from the controller 5 to the throttle motor 4 is controlled by turning the knob 10 without pushing it, and the rotational speed of the engine 1 can be controlled steplessly over the entire range via the governor device.
When the knob 10 is pushed, the shaft 11 comes into contact with the mode selection switch 17 and the sequentially set modes are switched. Therefore, the work mode is selected by pushing the number of times to obtain the desired mode.

In the example shown in FIGS. 4 and 5, the shaft of the knob 10 is composed of a hollow shaft 18 and a shaft 19 slidably fitted on the hollow shaft 18. The electrical contact piece 16 is attached to the hollow shaft 18.
A central portion 10 ′ of the knob is fixed to the upper end of the shaft 19, and a receiving seat 13 is fixed to the lower end portion, so that only the shaft 19 can be pushed.

4 and 5, the biasing spring 14 is provided between the switch body 12 and the receiving seat 13, so that the receiving seat 13 is always biased upward. In this case, the pushing operation of the knob pushes the central portion 10 'of the knob.
In addition, since the shaft 19 is only pushed, even if it rotates with the rotation of the hollow shaft 18, the pushing operation is not hindered.

  FIG. 6 shows how to switch the selection mode. FIG. 6A shows a cycle in which the mode switched by the push operation returns from the standard mode to the light excavation mode through the heavy excavation mode and returns to the standard mode. FIG. 6B shows a case where an automatic mode (A) for automatically switching the work mode in accordance with changes in work content is set. The standard mode (M) and the automatic mode (A) are alternately displayed. It shows that it switches to.

  In the throttle switch that also serves as the mode selection switch according to the present configuration, even when the mode is selected, the knob 10 can be rotated to operate the throttle, thereby further widening the workability of the construction machine. Can do.

The figure which shows the outline of the engine control mechanism which implemented this invention. External perspective view of the throttle switch of the present invention FIG. The external appearance perspective view which shows the other example of the throttle switch of this invention. FIG. Explanatory drawing which shows the mode switching point.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Variable hydraulic pump 3 Regulator 4 Throttle motor 5 Controller 6 Rotation sensor 7 Throttle switch 10 Knob 11 Shaft 12 Switch body 13 Receiving seat 14 Energizing spring 15 Electrical resistor 16 Electrical contact 17 Mode selection switch 18 Hollow shaft 19 Shaft

Claims (6)

  A switch body with a mode selection switch and an electrical resistor attached thereto is mounted with a knob that can be rotated and pushed via a shaft, and an electrical contact piece is attached to the shaft. Each time the knob is pressed, the mode to be selected can be switched sequentially, and the engine speed can be increased or decreased by rotating the knob. Throttle switch to do.   A knob is attached to a switch body to which a mode selection switch and an electric resistor are attached via a hollow shaft to which an electrical contact piece is attached, and the shaft is inserted and slidable in the axial direction of the hollow shaft. The mode selection switch is switched by pressing the button, and the mode to be selected can be sequentially switched each time the shaft is pressed, and the engine speed can be increased or decreased by rotating the knob. A throttle switch that doubles as a mode selection switch for construction machinery.   The mode switching switch for the construction machine according to claim 1 or 2, wherein the mode switched by the push operation is a standard excavation mode, a heavy excavation mode, and a light excavation mode, and the mode is switched to these modes sequentially. Throttle switch for combined use.   3. A throttle switch that also serves as a mode selection switch for a construction machine according to claim 1, wherein the mode that is switched by a push operation is a standard mode and an automatic mode, and the mode is switched alternately.   5. The mode selection switch according to claim 1, wherein the mode selection switch is a single-position stable switch that returns to its original position when the knob is not pushed. A throttle switch that doubles as a mode selection switch for construction machinery. A receiving seat is fixed to the shaft, and an urging means is provided between the receiving seat and the switch body. When the knob is not pushed, the shaft is returned to its original position by the urging force. A throttle switch that also serves as a mode selection switch for a construction machine according to claim 1, claim 2, claim 3, claim 4, or claim 5.