JPH01234606A - Expansion amount detection device for hydraulic cylinder - Google Patents

Abstract

PURPOSE:To enhance the detecting accuracy of a piston position by providing an well part on the external surface of a support body where a shaft connected to a piston is exposed, and fitting a detecting sensor to the external surface of the support body covering the well part. CONSTITUTION:A well part 24 is provided on the external surface of a support body 10 and a shaft 20 connected to a piston via a transmission mechanism 19 is faced to the well part 24. Furthermore, a potentiometer 18 as a detecting sensor is fitted to the external surface of the support body 10 covering the well part 24. According to the aforesaid construction, it is possible to continuously detect the expansion amount of the piston via the detection of the speed of the shaft 20 with the detecting sensor 18, and the support construction of the detecting sensor 18 can be made rigid, thereby ensuring a less influence due to an external disturbance and enhancing the detecting accuracy of the piston expansion amount.

Description

[Detailed description of the invention] A3 Purpose of invention (1) Industrial application fields The present invention relates to an expansion/contraction amount detection device for a hydraulic cylinder.

(2) Conventional technology Conventionally, in order to continuously detect the amount of expansion and contraction of a hydraulic cylinder, as disclosed in Japanese Utility Model Publication No. 56-13601, for example, a rotating shaft that is interlocked and connected to the hydraulic cylinder is used. It is common to connect a potentiometer to one end.

(3) Problems to be Solved by the Invention However, in the conventional system in which the potentiometer is supported by a cantilever type, the support structure is unstable, so it is difficult to control the expansion and contraction of the hydraulic cylinder. Precise control is difficult.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a hydraulic cylinder expansion/contraction amount detection device that has a simple configuration, improves detection accuracy, and is capable of continuously detecting the expansion/contraction amount of a hydraulic cylinder. purpose.

B1 Structure of the Invention (1) Means for Solving the Problems According to the present invention, a shaft is rotatably supported on a support body integral with the cylinder body of a hydraulic cylinder, and is interlocked and connected to a piston of the hydraulic cylinder. The interlocking member and the shaft are connected via a transmission mechanism that converts the movement of the interlocking member into rotational movement of the shaft, and the outer surface of the support body is provided with a recess that exposes the end of the shaft. A detection sensor connected to the shaft within the recess is attached to the outer surface of the support so as to continuously detect the amount of rotation, covering the recess.

(2) Effect According to the above configuration, the amount of expansion and contraction of the hydraulic cylinder is converted into the amount of rotation of the shaft via the transmission mechanism, and the amount of rotation of the shaft is detected by the detection sensor. It is possible to continuously detect the amount of expansion and contraction, and the detection sensor is directly attached to the support, making the support structure strong, and the connection part between the shaft and the detection sensor is also placed within the recess covered by the detection sensor. Therefore, it is less affected by disturbances and the detection accuracy is improved.

(3) Examples Hereinafter, an example in which the present invention is applied to a hydraulic cylinder for driving a ground work machine up and down in a traveling work vehicle will be explained with reference to the drawings. In the figures to FIG. 4, a ground working machine 2 such as a rotary tiller is connected to the rear of a tractor 1 as a traveling vehicle via a link mechanism 3. This link mechanism 3 has a 6-top link 4 and a pair of left and right lower links 5.5, and allows the ground work equipment 2 to move up and down relative to the tractor 1 and tilt left and right.

At the rear of the vehicle body 1a of the tractor 1, there is a
A rotating shaft 7 parallel to the rotational axes of the wheels W, W is rotatably supported, and a pair of left and right lift arms 8, 8 each have one end fixed to both ends of the rotating shaft 7. The other end and the intermediate portion of the lower links 5, 5 are connected to each other. Therefore, the ground working machine 2 moves up and down in response to the rotational movement of the rotational shaft 7. In addition, one of the lift arms 8 and the intermediate portion of the lower link 5 are connected via a tilting hydraulic cylinder 9, and the ground work machine 2 tilts left and right in response to the expansion and contraction of the tilting hydraulic cylinder 9. do.

The rotation shaft 7 is rotatably supported by a bracket 10 as a support, and this bracket IO is integrally connected to the cylinder body 11 of the hydraulic cylinder 12 to constitute a housing 13, and the housing 13 is fixedly installed at the rear of the vehicle body 1a. The cylinder body 11 of the hydraulic cylinder 12 is connected to the front part of the bracket 10 with an axis perpendicular to the axis of the rotation shaft 7, and rotates with a piston 14 that is slidably fitted into the cylinder body 11. The moving shaft 7 is connected. That is, a connecting rod 15 connected to the piston 14 connects a connecting pin 17 parallel to the rotating shaft 7 to the distal end of a swinging arm 16 serving as an interlocking member whose base end is fixed to the intermediate portion of the rotating shaft 7. connected via. Therefore, in response to the expansion and contraction of the hydraulic cylinder 12, the rotation shaft rotates back and forth within the range of angle α1.

On the other hand, both ends of the rotation shaft 7 protrude from both sides of the bracket 10, and one ends of lift arms 8, 8 are fixed to these protruding ends, respectively. Therefore, the reciprocating rotation of the rotation shaft 7 causes both the lift arms 8.degree. 8 to swing up and down, and the ground work machine 2 is moved up and down via the link mechanism 3.

A shaft 20 parallel to the rotation shaft 7 is rotatably supported on the bracket 10 at a position offset from the axis of the rotation shaft 7.
0 is connected to the swing arm 16 via a transmission mechanism 19. Moreover, in order to electrically and continuously detect the amount of expansion and contraction of the hydraulic cylinder 12, that is, the amount of rotation of the lift arms 8, 8,
A potentiometer 18 as a detection sensor is attached to one outer surface of the bracket 10 at a position corresponding to the shaft 20. The transmission mechanism 19 includes a link plate 21 having one end fixed to the inner end of the shaft 20, and a link plate 21 having the other end fixed to the shaft 20.
This is a link mechanism consisting of a link plate 23, one end of which is connected via a pin 22 parallel to the other end of the link plate 23, and the other end of which is connected to the swing arm 16.

As a result, the shaft 20 rotates in response to the rotational movement of the rotational shaft 7, that is, the swinging arm 16, and this transmission mechanism 19 The rotation amount α2 of 20 is set to have the following relationship.

α1≦α2 The shaft 20 is disposed such that its outer end faces a recess 24 provided on the outer surface of the bracket 10, and the potentiometer 18 is attached to the outer surface of the bracket 10 so as to cover the recess 24. The outer end of the shaft 20 is coaxially connected within the recess 24 .

Moreover, a coil spring 25 is interposed between the shaft 20 and the bracket 10 within the recess 24.
By rotationally biasing the shaft 20 in one direction, backlash in the transmission mechanism 19 is absorbed.

Next, the operation of this embodiment will be explained. In response to the expansion and contraction of the hydraulic cylinder 12, the rotation shaft 7 and the lift arm 8.8 rotate, and the ground work machine 2 is operated to raise and lower.

The lifting position of this ground work machine 2, that is, the hydraulic cylinder 12
The amount of expansion and contraction is continuously detected by transmitting the amount of swing of the swing arm 16, which swings in conjunction with the expansion and contraction operation of the hydraulic cylinder 12, to the potentiometer 18 via the transmission mechanism 19 and shaft 20. The amount of expansion and contraction of the hydraulic cylinder 12, that is, the vertical position of the ground work machine 2 is controlled according to the amount. At this time, since the rotation amount α1 of the swing arm 16 is set to be less than or equal to the rotation amount α2 of the shaft 20 (α1≦α2),
It is possible to accurately detect the amount of expansion and contraction of the hydraulic cylinder 12.

Furthermore, the potentiometer 18 is attached to the outer surface of the bracket 10 at a position offset from the axis of the rotation shaft 7. Therefore, it is not necessary to arrange the potentiometer 18 at an outer position along the axis of the rotation shaft 7, and the potentiometer 18
The amount of protrusion of the potentiometer 18 from the bracket 10 can be made extremely small, the mounting structure can be made compact, and the potentiometer 18 is protected from obstacles. Also, move potentiometer 18 to bracket 10
By attaching it directly to the holder, the structure of the mount becomes more robust. Furthermore, since the connecting portion between the shaft 20 and the potentiometer 18 is covered from the outside, it is less susceptible to external disturbances, and together with the fact that the support structure is strong, the detection accuracy can be improved.

5 and 6 show a second embodiment of the present invention, and parts corresponding to the first embodiment described above are given the same reference numerals.

A shaft 20' connected to a potentiometer 18 attached to the outer surface of the bracket 10 and a rotating shaft 7 as an interlocking member are interlocked and connected via a transmission mechanism 19'. This transmission mechanism 19' includes a driven gear 2 fixed to a shaft 20'.
6, and a drive gear 27 that meshes with the driven gear 26 and is fixed to the rotating shaft 7.

Also in this second embodiment, since the amount of rotation of the rotation shaft 7 is transmitted to the shaft 20' via the transmission mechanism 19', the amount of expansion and contraction of the hydraulic cylinder 12 can be continuously detected by the potentiometer 18. .

In the above embodiment, the recess 24 is formed on the outer surface of the bracket 10, but a plurality of protrusions are provided protruding from the bracket so as to form recesses between them, and a potentiometer 18 is mounted on the tip surface of the protrusions. You may also install it.

C8 Effects of the Invention As described above, according to the present invention, a shaft is rotatably supported on a support body integral with the cylinder body of a hydraulic cylinder, and an interlocking member interlocked and connected to a piston of the hydraulic cylinder and the shaft are connected to each other. are connected via a transmission mechanism that converts the movement of the interlocking member into rotational movement of the shaft, and the outer surface of the support body is provided with a recess that exposes the end of the shaft, so that the amount of rotation of the shaft can be continuously controlled. A detection sensor connected to the shaft within the recess for detection is attached to the outer surface of the support body covering the recess, so the amount of expansion and contraction of the hydraulic cylinder is converted to the amount of rotation of the shaft via the transmission mechanism, and the rotation of the shaft is By detecting the amount of movement with a detection sensor, it is possible to continuously detect the amount of expansion and contraction of the hydraulic cylinder.Moreover, with a simple configuration that does not require the conventional bracket, the support structure of the detection sensor is strong, and the influence of external disturbances can be detected. It is possible to improve the detection accuracy of the amount of expansion and contraction.

[Brief explanation of the drawing]

1 to 4 show a first embodiment of the present invention, in which FIG. 1 is a perspective view showing the rear part of the traveling work vehicle, FIG. 2 is an enlarged view of FIG. The figure is an enlarged sectional view taken along the line ■-■ in FIG. 2, FIG. 4 is a sectional view taken along the line ■-IV in FIG. 3, and FIGS. Fig. 5 is a sectional view corresponding to Fig. 3, and Fig. 6 is a cross-sectional view corresponding to Fig. 5.
FIG. 7... Rotating shaft as an interlocking member, 10... Bracket as a support body, 11... Cylinder body, 12...
- Hydraulic cylinder, 16... Swinging arm as an interlocking member, 18... Potentiometer as a detection sensor,
19.19'...Transmission mechanism, 20.20'...
Shaft, 24... recess

Claims (7)

[Claims] (1) A shaft is rotatably supported by a support that is integrated with the cylinder body of the hydraulic cylinder, and the shaft and the interlocking member that is interlocked and connected to the piston of the hydraulic cylinder control the operation of the interlocking member by rotating the shaft. The support body is connected via a transmission mechanism that converts it into motion, and the outer surface of the support body is provided with a recess that exposes the end of the shaft, and the support body is connected to the shaft within the recess in order to continuously detect the amount of rotation of the shaft. A device for detecting the amount of expansion and contraction of a hydraulic cylinder, characterized in that a detection sensor is attached to the outer surface of the support body so as to cover the recessed portion. (2) The apparatus for detecting the amount of expansion and contraction of a hydraulic cylinder according to item (1), wherein the detection sensor is an electric sensor. (3) The interlocking member is a swinging arm supported by a support body so as to be swingable about an axis perpendicular to the axis of the hydraulic cylinder, and the swinging arm and the shaft are connected via a transmission mechanism. The apparatus for detecting the amount of expansion and contraction of a hydraulic cylinder according to item (1) or item (2). (4) The device for detecting the amount of expansion and contraction of a hydraulic cylinder according to item (3), wherein the transmission mechanism is a link mechanism. (5) The interlocking member is a rotating shaft that is rotatable about an axis perpendicular to the axis of the hydraulic cylinder and supported by a support, and the rotating shaft and the shaft are connected via a transmission mechanism. The apparatus for detecting the amount of expansion and contraction of a hydraulic cylinder according to item (1) or item (2). (6) The transmission mechanism is a gear mechanism (
5) A hydraulic cylinder expansion/contraction amount detection device as described in item 5). (7) Items (3) and (4) characterized in that the transmission mechanism is configured such that the relationship between the rotation angle α1 of the interlocking member and the rotation angle α2 of the shaft is α1≦α2. , the expansion/contraction amount detection device for a hydraulic cylinder according to item (5) or item (6).