JPH0529929B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a detent device for holding a control lever in an operating position for issuing hoisting or other commands to a crane winch or the like.

[Prior Art] Conventionally, as a control lever detent device, one shown in FIG. 6 is known. This known example shows a case in which the invention is applied to a so-called remote control valve that operates a pilot pressure reducing valve by operating a lever.

In the figure, 1 is a control lever, 2 is a cam fixed to this control lever 1,
These rotate together around the horizontal axis 3. The push rods 4a and 5a of the pilot pressure reducing valves 4 and 5 are in contact with the bottom surface of the cam 2, and the rotation of the cam 2 operates one of the pressure reducing valves 4 or 5, and its secondary pressure causes the main control valve (not shown) to operate. is switched and operated to perform hoisting or hoisting operation.

Both sides of the cam 2 (hereinafter referred to as cam surfaces) 2a,
2a is provided with daytent recesses 6 at two locations corresponding to both lever operation positions (daytent positions), respectively. On the other hand, a piston case 8 is provided in the housing 7 in which the cam 2 is housed, and within this piston case 8, a piston 9 and
A push spring 10 is provided that presses the piston 9 toward the cam surface 2a. At the tip of the piston 9, there is a ball 11 that elastically contacts the cam surface 2a.
is held and in the day tent position, this ball 11
By engaging with the recess 6 of the cam 2, the cam 2, that is, the control lever, overcomes the spring reaction force of the pressure reducing valve 4 or 5 and is held at the detent position.

[Problem to be solved by the invention]

However, according to the above prior art, the ball 11
is always in contact with the cam surface 2a with a constant spring force, and this spring force is
Because it is relatively large enough to overcome the reaction force of the pressure reducing valve and hold it in the day tent position, there is a feeling of stiff resistance when operating the lever, giving a poor operating feeling and making lever operation unnecessarily heavy. .

In addition, in the control lever for crane winch control, in order to increase the operation reaction force in accordance with the increase in load (hanging load),
As shown in Japanese Patent No. 14199 and the like, load pressure of an actuator (hydraulic motor) or the like is applied to the control lever 1 as a lever operation reaction force. In this case, according to the prior art, as a result of the large operation resistance (hereinafter referred to as detent resistance) caused by the detent device, the proportion of the load reaction force in the total operation reaction force becomes small, and this load reaction force is transmitted to the driver. There was a problem that it became difficult.

Therefore, the present invention improves operability by exerting a large holding force only at the detent position and reducing the detent resistance at other times. To provide a control lever detent device that can reliably transmit load reaction force to a driver by increasing the ratio of load reaction force to the whole.

[Means to solve the problem]

The present invention consists of a cam that moves together with the control lever when the control lever is operated, a piston that is installed on a fixed part so that its tip comes into sliding contact with the cam when the cam moves, and a piston that is formed behind the piston. a pressure chamber provided in the pressure chamber, and a spring provided in the pressure chamber to press the piston toward the cam; A detent portion is provided at which the sliding resistance with the piston tip portion is greater than other portions at certain positions, and a detection means for detecting that the piston tip portion is located in the detent portion, and a detection signal from the detection means is based on the detent portion. and hydraulic pressure supply means for supplying hydraulic pressure to the pressure chamber.

Further, in the present invention, in the above configuration, an electric contact constituted by a piston and a cam is used as the detection means.

[Effect]

With this configuration, it is possible to reduce the daytent resistance at positions other than the daytent position, which improves operability.It also reduces the proportion of the daytent resistance in the total operation reaction force, that is, increases the proportion of the load reaction force, and allows the driver to It becomes possible to reliably transmit the load reaction force to the

Further, by using an electric contact constituted by a piston and a cam as the detection means, installation and adjustment of the detection means is not necessary, and therefore installation becomes easy. Furthermore, since it is hardly affected by vibrations of the aircraft body, the reliability of the detection operation is good.

〔Example〕

Embodiments of the present invention will be described with reference to FIGS. 1 to 5.

A first embodiment of the present invention is shown in FIGS. 1 and 2, a second embodiment is shown in FIG. 3, a third embodiment is shown in FIG. 4, and a fourth embodiment is shown in FIG. 5, respectively.

In each of these embodiments, in accordance with the conventional example, a control lever of a remote control valve for winch control is taken as an example of application.

First Embodiment (See Figures 1 and 2) In Figure 1, the basic configuration of the remote control valve that operates the pilot pressure reducing valve by operating the control lever is the same as the conventional example shown in Figure 6. Therefore, illustration of the control lever and pressure reducing valve is omitted, and only the detent device portion is shown. Further, since the configuration of this detent device is exactly the same on both sides of the cam, only one side is shown here.

Reference numeral 21 denotes a cam that rotates around a horizontal axis 22 together with the control lever when the control lever is operated.
Concave portions 23 and 23 as detent portions are provided at two upper and lower locations corresponding to both lever operation positions (detent positions) at 21a. On the other hand, a piston case 25 is attached to the housing 24 in which the cam 21 is housed, and a piston 26 and a push spring 27 for pressing the piston 26 toward the cam surface 21a are provided in the piston case 25. A cap 28 is attached to the rear end of the piston case 25 and also serves as a spring holder. A pressure chamber 29 is formed between the cap 28 and the piston 26 in the piston case 25.

The piston 26 also has a ball 30 at its tip.
is held, and this ball 30 is pressed against the push spring 27.
It comes into elastic contact with the cam surface 21a due to the spring force, and engages with the recess 23 at the detent position. In this case, the spring force of the push spring 27 is the minimum amount necessary to ensure the contact state between the ball 30 and the cam surface 21a throughout the entire lever stroke, and the spring force is the minimum amount necessary to maintain the contact state between the ball 30 and the cam surface 21a throughout the lever stroke, and to maintain the state in which the ball 30 is engaged with the recess 23. The cam 21 (control lever) is set to be so weak that it cannot be held in the day tent position by itself.

On the other hand, a rod 31 is integrally connected to the rear end of the piston 26 so as to pass through the cap 28, and this rod 31 controls the limit switch 3.
2 is now being operated.

33 is a hydraulic pump, and this hydraulic pump 33 is connected to a pressure chamber 29 in the piston case 25 via an electromagnetic switching valve 34 and a conduit 35. When the solenoid 34a is de-energized, the electromagnetic switching valve 34 is in the tank communication position a on the left side of the figure, and when the limit switch 32 is activated, the solenoid 34a is energized and switched to the pressure oil supply position b on the right side of the figure. In this state, pressure oil from the pump 33 is supplied to the pressure chamber 29, and hydraulic pressure acts on the pressure chamber 29.

In this way, at the detent position where the ball 30 engages with the recess 23, the spring force of the push spring 27 and the hydraulic pressure of the pressure chamber 29 are applied to the piston 26, and this total force is applied to the ball 30, so that the cam 21 (control lever) is held in the day tent position. That is, only in the daytent position, a large force that can overcome the pressure reducing valve reaction force and ensure the daytent function is applied to the control lever, and during other lever operations, the state of contact between the ball 30 and the cam surface 21a is ensured. Only a small spring force is applied. Therefore, compared to conventional devices in which a constant large spring force acts as daytent resistance, there is no harsh feeling during lever operation, and the overall operation reaction force is smaller, resulting in better operability. .

In addition, when applying a method of applying operational reaction force according to the load to the control lever, as the detent resistance becomes smaller, the proportion of the load reaction force in the total operational reaction force becomes relatively larger. Power can be reliably transmitted to the driver. In addition, in FIG. 1, 36 is a relief valve that sets the pressure in the pressure chamber 29. Also, to cancel the day tent,
This is done by cutting off the power to the solenoid 34a of the electromagnetic switching valve 34 by operating a separately provided release switch. Two examples of circuit configurations of this solenoid drive circuit are shown in FIGS. 2A and 2B.

In the circuit shown in FIG. 2A, two relays 37 and 38 are used, and the normally open contact 39 and solenoid 34a of the first relay 37 are used, and the normally open contact 39 and the solenoid 34a of the first relay 37 are A closing contact 40, a limit switch 32, a second relay 38 and a release switch 41 are each connected in series, and these three series circuits are connected in parallel between the power supplies.

In this circuit configuration, when the limit switch 32 is turned on at the detent position, the first relay 37 is activated and the solenoid 34a is energized.
The electromagnetic switching valve 34 switches to the pressure oil supply position b and operates. After that, when the release switch 41 is turned on, the second relay 38 is operated, and as a result, its normally closed contact 40 opens, the first relay 37 returns, and its normally open contact 39 opens, energizing the solenoid 34a. The circuit is interrupted.

On the other hand, in the circuit shown in FIG. 2B, a normally closed switch is used as the limit switch 32,
This limit switch 32 and release switch 41 are connected in parallel, and this parallel circuit and relay 42 are connected in series. Further, the normally closed contact 43 of this relay 42 and the solenoid 34a are connected in series between the power supplies.

In this circuit configuration, the limit switch 32
Since the relay 42 is a normally closed switch, the relay 42 is activated at positions other than the detent position, its normally closed contact 43 is open, and the solenoid 34a is de-energized. When the limit switch 32 is turned off at the detent position by the movement of the rod 31 shown in FIG. 1, the relay 42 returns to its normal state and its normally closed contact 43 closes, forming an energizing circuit for the solenoid 34a. When the release switch 41 is turned on, the relay 42 is activated again and the normally closed contact 43 is turned on.
is opened, and power supply to the solenoid 34a is cut off.

Of the two circuits mentioned above, the configuration shown in FIG. 2B has a simple configuration. On the other hand, according to the configuration in A, although the configuration is somewhat complicated, relays 37 and 38
In the event of a failure such as a disconnection of the wire, the daytent function is only disabled, and there is no inconvenience that would occur if the function were to remain in effect, so it has the advantage of having a so-called fail-safe function.

Second Embodiment (See Fig. 3) If the daytent function is not required due to work that requires frequent lever operations, according to the above embodiment, it is necessary to operate the release switch 41 shown in Fig. 2 each time the lever is operated. .

Therefore, in the second embodiment, the electromagnetic switching valve 3
An electromagnetic switching valve 44 is provided in the conduit 35 connecting the pressure chamber 29 and the pressure chamber 29, and the electromagnetic switching valve 44 is controlled by a selection switch (not shown). In this way, by setting the electromagnetic switching valve 44 to the tank communication position shown in the figure when the detent function is not required, the detent function can be disabled at all times during work, so the release switch 41 can be pressed every time the lever is operated. It can save you the trouble of operating it.

By the way, as a sensor for detecting engagement of the ball 30 with the recess 23 by movement of the piston 26, a proximity switch or an optical sensor may be used in place of the limit switch 32 used in both the first and second embodiments. Good too.

Third Embodiment (see FIG. 4) and Fourth Embodiment (see FIG. 5) In the case of a configuration in which the ball 30 is engaged with the recess 23 to hold the control lever at the detent position, the amount of movement of the ball 30, i.e. piston 26
The movement stroke is usually small, about 0.5 mm to 1 mm. For this reason, the ball 30
In the case of the configuration of both the first and second embodiments described above, in which engagement with the piston 26 must be detected by a very small change in the stroke of the piston 26, the mounting adjustment of the sensor (limit switch 32 or proximity switch, optical sensor) is difficult. It becomes troublesome. In addition, there is a risk that the adjustment may be disrupted due to vibrations of the machine during work.

In addition, as a countermeasure for this point, it is possible to make the recess 23 deeper and increase the stroke of the piston 26, but in this case, the ball 30 is pushed into the recess 23.
The force required to release the detent from the detent, that is, the detent release force, increases, resulting in poor operability.

Therefore, in both the third and fourth embodiments, instead of detecting the movement of the piston 26, the movement of the piston 26 is detected.
and cam 21 constitute an electrical contact, and ball 3
0 and the recess 23 are directly detected as opening and closing of the contacts.

That is, in the third embodiment, the cap of the piston case 25 is formed by forming the piston case 25 from ceramic such as aluminum oxide, rubber or other electrically insulating material, and by forming all other constituent members from conductive materials. 28-Press spring 27-Piston 26-Ball 30-Cam 21-
A series circuit is formed in which the horizontal shaft 22, which is a cam fulcrum, is connected to a housing 24 (grounded to the body) to which the horizontal shaft 22 is attached.

This series circuit is connected to a power source (battery) 46 via a relay 45, and a normally closed contact 47 of this relay 45 is inserted into the energizing circuit for the solenoid 34a of the electromagnetic switching valve 34.

On the other hand, on the surface of the recess 23 that comes into contact with the ball 30,
An insulating layer 48 made of the same electrically insulating material as the piston case 25 is provided.

In this way, when the ball 30 engages with the recess 23, the piston 26 and the cam 21 are in a disconnected state (contacts OFF), and in other states, they are in a energized state (contacts ON). .

In addition, in the case of the third and fourth embodiments, the rod 31 of both the first and second embodiments is unnecessary.

In the contact ON state, the relay 45 is energized and operates, and its normally closed contact 47 is opened, thereby cutting off the energization circuit of the solenoid 34a. Therefore, since the electromagnetic switching valve 34 is in the tank communication position a, no hydraulic pressure is supplied to the pressure chamber 29.

Then, the ball 30 is placed in the recess 2 at the day tent position.
3 and turns off the contact, the relay 45 stops and the normally closed contact 47 closes, so the electromagnetic switching valve 34 switches to the pressure oil supply position b, and hydraulic pressure is supplied to the pressure chamber 29. .

On the other hand, in the fourth embodiment, the configuration is opposite to that of the third embodiment, that is, in addition to the piston case 25, the cam 21 is also formed of an electrically insulating material, and the recess 23
A conductive layer 49 made of a conductive material is provided on the contact surface with the ball 30, and a lead wire 50 is wired between the conductive layer 49 and the horizontal shaft 22 inside the cam 21.
connected by.

Further, a normally open contact 51 of a relay 45 is inserted into the energizing circuit for the solenoid 34a of the electromagnetic switching valve 34.

Therefore, in the case of this fourth embodiment, when the ball 30 engages with the recess 23 at the detent position,
The contact is turned on, the relay 45 is activated, the solenoid 34 is energized, and hydraulic pressure is supplied to the pressure chamber 29.

According to both the third and fourth embodiments, the piston 26 and the cam 21 constitute an electrical contact, and the electromagnetic switching valve 34 is controlled by opening and closing this contact. This eliminates the need for the troublesome adjustment of mounting the sensor as in the first and second embodiments in which the movement of the piston 26 is detected by a sensor. Furthermore, there is no problem of adjustment errors due to vibration of the aircraft body, and detection reliability is improved.

Incidentally, in each of the above embodiments, the recess 23 as a detent portion is provided on the cam 21 side, and the ball 30 is provided on the opposite piston 26 side.However, conversely, a ball or ball-shaped portion as a detent portion is provided on the cam side. A recess into which the projection can be engaged may be provided on the piston side.

Furthermore, when using an electric contact constituted by a piston and a cam as the detection means, it is not necessary to constitute the electric contact by a protrusion and a recess as in the third and fourth embodiments. Not,
For example, the detent portion on the cam side may be a stopper that comes into contact with the piston to prevent further rotation of the cam, or a concavo-convex portion that increases the sliding resistance of the piston.

〔Effect of the invention〕

As described above, according to the present invention, when the control lever is in the daytent position, hydraulic pressure is supplied to the pressure chamber formed behind the piston to exert the daytent function, so that the daytent resistance at positions other than the daytent position is minimized. can be made as small as possible. Therefore, in addition to improving operability, when applying a method of applying operational reaction force to the control lever according to the load, the proportion of detent resistance in the total operational reaction force can be reduced, that is, the proportion of load reaction force can be increased. This makes it possible to reliably transmit the load reaction force to the driver.

Further, according to a configuration that detects that the control lever has reached the daytent position by an electric contact formed by a piston and a cam, it is detected that the control lever has reached the daytent position by movement of the piston. Compared to the conventional case, there is no need to adjust the installation of the detection means, making installation easier. Furthermore, since it is hardly affected by vibrations of the aircraft body, the reliability of the detection operation is good.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a first embodiment of the present invention, Fig. 2 A and B are circuit diagrams showing two examples of a drive circuit for a solenoid of an electromagnetic switching valve in the device of the same embodiment, and Fig. 3 is a diagram showing a drive circuit of a solenoid of an electromagnetic switching valve in the same embodiment. FIG. 4 is a diagram corresponding to FIG. 1 showing the third embodiment, FIG. 5 is a diagram corresponding to the fourth embodiment, and FIG. 6 is a diagram showing a conventional example. 21... cam, 23... recessed part as a day tent part of the cam, 24... housing of the remote control valve as a fixed part, 25... piston case, 26
... Piston, 29 ... Pressure chamber, 30 ... Ball as projection, 32 ... Limit switch as detection means, 33 ... Pump constituting hydraulic pressure supply means, 34 ... Solenoid switching valve, 48 ... Piston an electrically insulating layer for forming an electrical contact by the and cam; 49...the electrically conductive layer;

Claims (1)

[Scope of Claims] 1. A cam that moves together with the control lever when the control lever is operated, a piston that is provided on a fixed part so that its tip comes into sliding contact with the cam as the cam moves, and the piston of this piston. The cam includes a pressure chamber formed behind the pressure chamber, and a spring provided in the pressure chamber to press the piston toward the cam. A detent portion is provided in which sliding resistance with the piston tip portion is greater than other portions at the detent position of the lever, and a detection means for detecting that the piston tip portion is located in the detent portion, and detection from the detection means A control lever detent device comprising: hydraulic pressure supply means for supplying hydraulic pressure to the pressure chamber based on a signal. 2. A control lever detent device characterized in that the detection means is an electric contact constituted by a piston and a cam.