Multiple lever mechanism
The multi-lever mechanism for heavy construction equipment addresses the challenge of reducing overall width by using a single rotational shaft for multiple operating levers and optimizing the placement of detection components, resulting in a more compact design that fits within tighter spaces and reduces costs.
Patent Information
- Application Number
- JP2023149934
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-09-15
- Publication Date
- 2025-03-28
AI Technical Summary
Conventional multi-lever mechanisms for heavy construction equipment, such as cranes, face challenges in reducing overall width due to the installation of multiple operating levers, which increases the dimensions of each frame and requires more space within the operator cabin.
The multi-lever mechanism incorporates multiple operating levers supported by a single rotational shaft, with a rotation angle detection unit that includes a non-contact sensor and a detection unit positioned away from the rotational shaft. This configuration allows for reduced width by eliminating the need for additional frames and optimizing the placement of detection components.
This solution effectively reduces the overall width of the multi-lever mechanism, allowing it to be installed in tighter spaces within the operator cabin of heavy construction equipment, while also reducing costs by minimizing the number of frames required.
Smart Images
Figure 2025042792000001_ABST
Abstract
Description
[Technical field]
[0001] The present invention relates to a multiple lever mechanism for operating heavy construction machinery such as a crane. [Background technology]
[0002] 2. Description of the Related Art In heavy construction machinery, such as a crane, a number of operations, such as raising and lowering the boom, rotating the boom, and winding up and down the wire, are each operated by an independent control lever. An operating lever for controlling the up and down movement of the boom is rotatable in the front-rear direction about a rotation axis, and the amount of up and down movement of the boom is controlled according to the rotation angle of the operating lever.
[0003] An example of this type of operating lever is Patent No. 6471083.
[0004] [Patent Document 1] Patent No. 6471083 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]
[0005] However, in the case of heavy construction machinery such as cranes, the operating cabin into which the operator sits cannot have the operating levers placed at the front in order to ensure forward visibility, and so operating levers are instead placed on both sides of the operator. It is desirable to arrange multiple operating levers on the side of the operator in a horizontal row in consideration of operability.
[0006] This type of lever mechanism has an operating lever that is supported rotatably about a rotation shaft suspended across a frame, and an angle detection unit that detects the rotation angle of this operating lever. The angle detection unit includes a radially magnetized magnet that is attached to the end of the rotating shaft and rotates with the rotation of the rotating shaft, and a Hall element that serves as a non-contact sensor that detects the position of the magnet.
[0007] However, in conventional lever mechanisms, a magnet is installed at the end of the rotating shaft and a Hall element as a non-contact sensor is installed facing this magnet, so the width dimension is increased by at least the dimensions of the magnet, the Hall element, and the gap between them. Furthermore, in this conventional lever mechanism, one operating lever is housed in one frame, so when multiple levers are arranged in a horizontal row, the overall width dimension tends to become large due to the combined dimensions of each frame. Since the operating cabin has only a minimum amount of space, the width of the lever mechanism needs to be small.
[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a multiple lever mechanism which can reduce the overall width dimension and reduce costs. [Means for solving the problem]
[0009] The multiple lever mechanism of the present invention comprises a plurality of operating levers rotatably supported on the same rotating shaft, a rotation angle detection unit which detects the rotation angles of these operating levers, and a frame which supports the rotating shaft and houses the plurality of operating levers inside, the rotation angle detection unit having a non-contact sensor and a detectable part which is detected by the non-contact sensor, the non-contact sensor and the detectable part being installed at a position away from the rotating shaft, the detectable part being displaced circumferentially around the rotating shaft in response to the rotation of the operating lever, and the non-contact sensor is not displaced regardless of the rotation of the operating lever.
[0010] Further, a magnetic sensor or an optical sensor is used for the non-contact sensor, and a magnet magnetized in the height direction or a light emitting element is used for the detected portion.
[0011] In order to detect the direction of rotation of the operating lever, two switches that react according to the direction of rotation of the operating lever are provided.
[0012] A return mechanism for returning the operating lever to a neutral position is provided for each lever.
[0013] Further, an operating lever fixing mechanism for fixing the operating lever in the neutral position is provided for each operating lever. Effect of the Invention
[0014] The multiple lever mechanism of the present invention houses multiple operating levers in a single frame, so that at least the width dimension of the frame can be made smaller than in the case where multiple frames, each housing a single operating lever, are lined up in a row horizontally, resulting in a multiple lever mechanism with a reduced overall width. Furthermore, the number of frames can be reduced compared to conventional devices, leading to cost reduction.
[0015] Furthermore, in the multiple lever mechanism according to the present invention, the rotation angle detection unit is not disposed in the longitudinal direction of the rotating shaft, so that the overall width dimension can be reduced. [Brief description of the drawings]
[0016] [Figure 1] FIG. 1 is a schematic exploded perspective view showing an operating lever that constitutes a multiple lever mechanism according to an embodiment of the present invention, a rotation angle detection unit that detects the rotation angle of this operating lever, and a return mechanism that automatically returns this operating lever to a neutral position, as viewed from the return mechanism side. [Diagram 2] FIG. 1 is a schematic exploded perspective view showing an operating lever that constitutes a multiple lever mechanism according to an embodiment of the present invention, a rotation angle detection unit that detects the rotation angle of this operating lever, and a return mechanism that automatically returns this operating lever to a neutral position, as viewed from the rotation angle detection unit side. [Diagram 3] 1 is a schematic side view of a multiple lever mechanism according to an embodiment of the present invention; [Figure 4] 1 is a schematic plan view of a multiple lever mechanism according to an embodiment of the present invention; [Diagram 5]2 is a schematic cross-sectional view taken along line VV of a multiple lever mechanism according to an embodiment of the present invention. FIG. [Figure 6] 6 is a schematic cross-sectional view of a multiple lever mechanism according to an embodiment of the present invention taken along line VI-VI. FIG. [Figure 7] 7 is a schematic cross-sectional view taken along line VII-VII of a rotation angle detection portion of an operating lever that constitutes the multiple lever mechanism according to the embodiment of the present invention. FIG. [Figure 8] 2 is a schematic perspective view of a frame that constitutes the multiple lever mechanism according to the embodiment of the present invention. FIG. [Figure 9] 1A is a schematic perspective view of a sensor mounting member constituting a multiple lever mechanism according to an embodiment of the present invention, FIG. 1B is a schematic side view, FIG. 1C is a schematic front view, and FIG. 1D is a schematic plan view. [Figure 10] FIG. 1 is a schematic plan view of a multiple lever mechanism in which a brake mechanism is provided on only one operating lever. [Figure 11] FIG. 1 is a schematic side view of a multiple lever mechanism in which a brake mechanism is provided on only one operating lever. [Figure 12] FIG. 2 is a schematic exploded perspective view of a brake mechanism having only one operating lever. [Figure 13] FIG. 11 is a schematic cross-sectional view of a brake mechanism having only one operating lever. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] A multiple lever mechanism 1000 according to an embodiment of the present invention includes three operating levers 100A, 100B, 100C rotatably supported on a single rotating shaft 400, three rotation angle detection units 200A, 200B, 200C that detect the rotation angles of these three operating levers 100A, 100B, 100C, and a frame 300 that supports the rotating shaft 400 and houses the three operating levers 100A, 100B, 100C therein. The rotation angle detection units 200A, 200B, 200C include non-contact sensors 210A, 210B, 210C, and the non-contact sensors 210A, 210B, 210C. The non-contact sensors 210A, 210B, 210C and the detected parts 220A, 220B, 220C are installed at positions away from the rotation axis 400, and the detected parts 220A, 220B, 220C are displaced circumferentially about the rotation axis 400 in response to the rotation of the operating levers 100A, 100B, 100C, while the non-contact sensors 210A, 210B, 210C do not displace regardless of the rotation of the operating levers 100A, 100B, 100C.
[0018] This multiple lever mechanism 1000 is used, for example, to operate a crane, with each operating lever 100A, 100B, 100C responsible for the up and down movement of the boom, the swinging movement of the boom, and the winding up and rewinding of the wire, respectively. It should be noted that this multiple lever mechanism 1000 is not limited to use with cranes, and the respective operating levers 100A, 100B, 100C are not responsible for the up and down movement of the boom, the rotation of the boom, or the winding up and down of the wire, but are generally usable with many types of heavy construction machinery. Furthermore, this multiple lever mechanism 1000 is not limited to three operating levers 100A, 100B, 100C, and there are also mechanisms having two operating levers, or four or more operating levers.
[0019] Since the three operating levers 100A, 100B, and 100C have the same structure, the structure of the operating lever 100A will be described, and descriptions of the structures of the operating levers 100B and 100C will be omitted. However, in Fig. 1, the members constituting the operating lever 100A are given the reference numbers of the operating levers 100B and 100C.
[0020] The operating lever 100A has a lever shaft 110A and a lever base 120A to which the lever shaft 110A is attached. Lever shaft 110A is the part that is operated by the operator, and is sized and shaped to be easy to grip.
[0021] The lever base 120A has a lever shaft attachment portion 121A to which the lever shaft 110A is attached. Furthermore, this lever shaft attachment portion 121A is provided with a through hole 123A through which the rotating shaft 400 passes. Furthermore, a detection target attachment piece 124A extends from this lever shaft attachment portion 121A and expands in a direction perpendicular to a rotation axis 400 passing through through hole 123A. A circular recess 125A is formed in this detection target attachment piece 124A at a position away from through hole 123A. This recess 125A is for attaching a detection target 220A, which will be described later.
[0022] An outwardly protruding convex portion 126A is formed on the edge of the detection target attachment piece 124A. This convex portion 126A is formed along the up-down direction of the concave portion 125A. Therefore, this convex portion 126A moves in the circumferential direction around the rotation shaft 400 in response to the rotational movement of the operating lever 100A. The protruding portion 126A is a portion for operating two switches 250A and 260A, which will be described later, and both side ends thereof form stepped portions 128A.
[0023] On the other hand, an operating lever fixing piece 127A is formed to extend from the lever shaft attachment part 121A of the lever base 120A on the opposite side of the through hole 123A to the recess 125A. This operating lever fixing piece 127A also extends in a direction perpendicular to the rotation axis 400 passing through the through hole 123A, similar to the detection target attachment piece 124A. A fixing recess 129A, which is a recess, is formed on the edge of this operating lever fixing piece 127A, and a fixing stopper 600A, which will be described later, is inserted into this fixing recess 129A to fix the operating lever 100A and prevent it from rotating. The fixing recess 129A is formed at a position where the fixing stopper 600A can be inserted when the lever shaft 110A is in the neutral position.
[0024] Furthermore, a return projection 540A constituting a part of a return mechanism 500A (to be described later) is formed on the outer surface of the lever shaft attachment portion 121A of the lever base 120A so as to protrude directly above the through hole 123A.
[0025] The operating lever 100A constituting this multiple lever mechanism 1000 is in a neutral position when no external force is applied. In other words, even if the lever shaft 110A is rotated, if the operator releases his / her hand, the lever shaft 110A automatically returns to the neutral position. The return mechanism 500A that brings about such a return to the neutral position is configured as follows: two return levers 510A, 520A, a return coil spring 530A suspended between the return levers 510A, 520A, the above-mentioned return protrusion 540A, and a return reference pin 550 located directly below the return protrusion 540A. The two return levers 510A and 520A constituting the return mechanism 500A are installed on one side of the lever base 120A.
[0026] 1 etc., the return levers 510A, 520A are single plates with openings 511A, 521A through which the rotary shaft 400 passes, and upper contact pieces 512A, 522A are formed above the openings 511A, 521A, and lower contact pieces 513A, 523A are formed below the openings 511A, 521A. That is, the upper contact pieces 512A, 522A and the lower contact pieces 513A, 523A are formed on either side of the openings 511A, 521A. Coil spring stopper portions 514A and 524A are formed extending further downward from the lower contact pieces 513A and 523A. Moreover, the coil spring stopper portions 514A and 524A are formed with hook recesses 515A and 525A facing outward, on which the return coil spring 530A is hooked.
[0027] The two return levers 510A, 520A are symmetrically arranged on the left and right sides, and the rotation shaft 400 passes through the openings 511A, 521A. In other words, if the upper contact piece 512A of one return lever 510A is positioned on the right side and the lower contact piece 513A is positioned on the left side, the upper contact piece 522AA of the other return lever 520A is positioned on the left side and the lower contact piece 523A is positioned on the right side.
[0028] The return reference pin 550 is a pin provided parallel to the rotating shaft 400 on the lower side of the rotating shaft 400, and is hung between the frame side walls 310 of the frame 300 described later. The return reference pin 550 is positioned in a straight line together with the return projection 540A and the openings 511A and 521A.
[0029] The return mechanism 500A is formed by passing the rotating shaft 400 through the through hole 123A of the lever base 120A, and then passing the rotating shaft 400 through the openings 511A and 521A of the two return levers 510A and 520A, and hooking the return coil spring 530A into the hooking recesses 515A and 525A of the coil spring stop portions 514A and 524A of the two return levers 510A and 520A.
[0030] Furthermore, a fixing stopper 600A serving as an operating lever fixing mechanism is inserted into the fixing recess 129A, thereby fixing the operating lever 100A and preventing it from rotating. Moreover, the fixing recess 129A is formed at a position where the fixing stopper 600A can be inserted when the lever shaft 110A is in the neutral position. This operating lever fixing mechanism is designed to prevent inadvertent operation of the operating lever 100A, thereby ensuring safety.
[0031] The return mechanism 500A configured in this manner operates as follows. First, when no external force is applied to the lever shaft 110A, the lever shaft 110A is located in a neutral position. That is, the lever shaft 110A stands upright, the upper contact pieces 512A and 522A of the two return levers 510A and 520A are positioned in contact with the return protrusion 540A from both sides, and the lower contact pieces 513A and 523A are also positioned in contact with the return reference pin 550. The return coil spring 530A acts to press the lower contact pieces 513A and 523A of the two return levers 510A and 520A against the return reference pin 550.
[0032] When the shaft lever 110A is rotated from this neutral position around the rotation shaft 400 in the clockwise direction in FIG. 6, the lever base 120A also rotates around the rotation shaft 400 in conjunction with the rotation of the shaft lever 110A. Then, one of the return levers 510A is pushed by the return projection 540A and rotates clockwise. At the same time, the lower contact piece 513A of the return lever 510A rotates clockwise and moves away from the return reference pin 550. At that time, since the return coil spring 530A is stretched, the shaft lever 110A rotates against the elastic force of the return coil spring 530A.
[0033] At this time, the other return lever 520A maintains the initial state regardless of the displacement of the one return lever 510A because the lower contact piece 523A of the other return lever 520A is in contact with the return reference pin 550. In other words, the lower contact piece 523A of the other return lever 520A maintains the state of contacting the return reference pin 550. Incidentally, since the lever base 120A rotates clockwise in accordance with the rotation of the lever shaft 110A, the upper contact piece 522A of the other return lever 520A is not in contact with the return projection 540A of the lever base 120A.
[0034] When the operator releases the force applied to lever shaft 110A from this state, lever shaft 110A naturally returns to its original position in the counterclockwise direction due to the elastic force of return coil spring 530A. When the force rotating the lever shaft 110A in the clockwise direction is completely released, the upper contact piece 512A of one return lever 510A rotates in the counterclockwise direction due to the elastic force of the return coil spring 530A, and the return protrusion 540A of the lever base 120A returns until it contacts the upper contact piece 522A of the other return lever 520A. At the same time, the lower contact piece 513A of one return lever 510A contacts the return reference pin 550. That is, the lever shaft 110A naturally and reliably returns to the neutral state without the operator having to consciously operate the lever shaft 110A. This automatic return to the neutral position also helps prevent unnecessary operating errors by the operator.
[0035] When the lever shaft 110A is rotated counterclockwise, the other return lever 520A rotates counterclockwise in conjunction with the rotation of the lever base 120A, which is the opposite of the case of the one return lever 510A described above. In this case, the one return lever 510A does not rotate. When the counterclockwise force on lever shaft 110A is released, lever shaft 110A naturally returns to the clockwise direction due to the elastic force of return coil spring 530A.
[0036] When the force rotating the lever shaft 110A counterclockwise is completely removed, the upper contact piece 522A of the other return lever 520A rotates clockwise due to the elastic force of the return coil spring 530A, and the return protrusion 540A of the lever base 120A returns until it contacts the upper contact piece 512A of the one return lever 510A. At the same time, the lower contact piece 523A of the other return lever 520A contacts the return reference pin 550. That is, the lever shaft 110A naturally returns to the neutral state without the operator having to consciously operate the lever shaft 110A.
[0037] On the other hand, the rotation angle detection unit 200A, which detects the rotation angle of the operating lever 100, has a magnet as the detected part 220A, a Hall element as the non-contact sensor 210A that detects the displacement of the magnet as the detected part 220A, and a sensor mounting member 230 that is fixed to the frame 300 so as to install the Hall element at a predetermined distance from the magnet.
[0038] The magnet as the detected part 220A is placed in the recess 125A of the detected part attachment piece 124A of the lever base 120A. This magnet as the detected part 220A is formed in a circular shape so as to fit into the recess 125A, and is magnetized in the height direction. Note that magnetization in the height direction means that the magnet is magnetized with a north pole or a south pole in the height direction (thickness direction) of the magnet. In other words, the front side of the magnet is magnetized with a north pole or a south pole, and the back side is magnetized with a north pole or a south pole. Since the lever base 120A rotates in accordance with the rotation of the lever shaft 110A, the magnet which is the detected part 220A also rotates in accordance with the rotation of the lever shaft 110A.
[0039] A Hall element is used as the non-contact sensor 210A for detecting the displacement of the detection target portion 220A. As shown in FIG. 1 and other figures, the non-contact sensor 210A has a rectangular main body and a pair of mounting parts protruding from the main body. This non-contact sensor 210A is attached to a sensor attachment member 230A provided on the opposite side of the lever base 120A from the side on which the return mechanism 500A is installed, by utilizing a screw hole in the attachment portion.
[0040] As shown in FIG. 9 etc., the sensor mounting member 230A is a plate material having a first surface 231A on which the non-contact sensor 210A is mounted, and a second surface 232A formed integrally by bending an edge of the first surface 231A. In addition, an oval opening 233A is provided on the first surface 231A so that the attached non-contact sensor 210A and the detected part 220A face each other. This opening 233A corresponds to the trajectory of the detected part 230A attached to the lever base 120A as the lever base 120A rotates about the rotation axis 400.
[0041] The second surface 232A of the sensor mounting member 230A is a portion on which the two switches 250A and 260A described above are mounted.
[0042] These two switches 250A, 260A are for determining the rotation direction of the operating lever 100A, i.e., whether it is clockwise or counterclockwise, and are operated by a convex portion 126A formed on the edge of the magnet mounting piece 124A of the lever base 120A. The actuator portions 251A, 261A of the switches 250A, 260A are in contact with a step portion 128A of the convex portion 126A, and when the lever base 120A rotates, the actuator portions 251A, 261A of the switches 250A, 260A on the rotating side are pressed and turned on.
[0043] For example, when the lever shaft 110A is rotated clockwise in the state shown in Fig. 6, the clockwise rotation of the lever base 120A turns on the switch 250A. When the switch 250A is turned on, it can be determined that the lever shaft 110A has been rotated clockwise.
[0044] As shown in FIG. 7, the rotation angle detection unit 200A is configured such that a Hall element serving as a non-contact sensor 210A mounted on a sensor mounting plate member 230A and a magnet serving as a detection target 220A mounted on the detection target mounting piece 124A of the lever base 120A face each other with a certain gap therebetween.
[0045] When lever shaft 110A is rotated, the magnet as detection part 220A attached to lever base 120A also rotates in the same manner, changing the positional relationship between the magnet as detection part 220A and the Hall element as non-contact sensor 210A, and the amount of displacement is detected by the Hall element as non-contact sensor 210A.
[0046] The operating levers 100B and 100C other than the operating lever 100A described above have the same structure as the operating lever 100A, and only differ in the reference characters A, B, and C.
[0047] As shown in FIG. 5, three of the operating levers 100A, 100B, 100C configured as described above are set on one frame 300. As shown in Figure 8 etc., this frame 300 has opposing frame side walls 310 formed thereon, and one rotation shaft 400 common to the three operating levers 100A, 100B, 100C and one return reference pin 550 parallel to this rotation shaft 400 are suspended between these frame side walls 310.
[0048] In the above-mentioned multiple lever mechanism 1000, the three operating levers 100A, 100B, 100C are contained in one frame 300, thereby reducing the overall width dimension of the multiple lever mechanism 1000. Furthermore, unlike conventional mechanisms, the detection portions 220A, 220B, 220C that constitute the rotation angle detection units 200A, 200B, 200C that detect the rotation angles of each operating lever 100A, 100B, 100C are located away from the rotation axis 400, thereby reducing the width dimension in the rotation axis direction and ultimately the overall width dimension of the multiple lever mechanism 1000.
[0049] Therefore, with this multiple lever mechanism 1000, it becomes possible to install it with ample space even in the operation cabin of a heavy construction machine such as a crane, which does not have much space in the width direction.
[0050] In addition, since this multiple lever mechanism 1000 is constructed by housing three operating levers 100A, 100B, 100C in a single frame 300, it has the advantage that it can be provided at a lower cost than the conventional method of housing multiple operating levers in a single frame and using them side by side.
[0051] In the above-described embodiment, the non-contact sensors 210A, 210B, and 210C use Hall elements, but other suitable magnetic sensors, such as MR sensors, AMR sensors, GMR sensors, TMR sensors, SQUIDs, etc., may also be used.
[0052] Furthermore, in addition to magnetic sensors, optical sensors such as CdS cells, infrared sensors, ultraviolet sensors, photodiodes, phototransistors, etc. may be used as appropriate, and light-emitting diode elements, laser diodes, etc. may be used as the detected parts as appropriate.
[0053] Moreover, the multiple lever mechanism 1000 according to the embodiment described above is configured so that the operating levers 100A, 100B, 100C are located in the neutral position when no external force is applied. This is because the multiple lever mechanism 1000 has a return mechanism 500 which returns the operating levers 100A, 100B, 100C to the neutral position when no external force is applied to them.
[0054] However, the multiple lever mechanism 1000 according to the present invention does not have this return mechanism 500, and has a brake mechanism 900 instead. For example, as shown in FIGS. 10 to 13, an operating lever 100A does not have a return mechanism 500A, and instead has a brake mechanism 900. In addition to the brake mechanism 900, for example, the non-contact sensors 210A, 210B, and 210C that detect the rotation of the operating levers 100A, 100B, and 100C, and the detected parts 220A, 220B, and 220C are configured the same as those described above.
[0055] The brake mechanism 900 rotates together with the operating lever 100A and includes a brake boss 910 having a cylindrical portion 913 coaxial with the rotation shaft 400, and a pair of brake shoes 920 that sandwich the cylindrical portion 913 from both sides.
[0056] As shown in Figure 12 etc., the brake boss 910 is integrally formed with an opening 912 provided in a plate 911, a cylindrical portion 913 that protrudes outward coaxially with the opening 912, and a recess 914 into which a brake protrusion 930 provided at a position similar to that of a return protrusion 540A that constitutes part of the return mechanism 500A fits. Therefore, the brake boss 910 rotates together with the operating lever 100A.
[0057] On the other hand, the brake shoe 920 has an arc-shaped recess 921 formed therein that corresponds to the outer peripheral surface of the cylindrical portion 913, and on both the upper and lower sides of this recess 921 are formed female threaded portions 922 into which two connecting screws 923 for connecting the brake shoes 920 together are screwed. Furthermore, at the lower end of this brake shoe 920, fixing convex portions 924 are formed which sandwich the return reference pin 550 from both sides so that the brake shoe 920 is not affected (fixed) by the rotation of the operating lever 100A.
[0058] A spring 925 is fitted onto one of the two connecting screws 923 that connect the pair of brake shoes 920. The spring 925 provides play in the sliding force of the brake shoes 920 against the cylindrical portion 913.
[0059] The brake mechanism 900 configured in this manner can apply a brake sliding force to the rotation of the operating lever 100A, thereby preventing inadvertent rotation of the operating lever 100A.
[0060] In the above embodiment, the brake mechanism 900 is provided only on the operating lever 100A among the three operating levers 100A, 100B, 100C, but it goes without saying that the brake mechanism 900 can also be provided on this operating lever. [Explanation of symbols]
[0061] 100A, 100B, 100C Operating lever 200A, 200B, 200C Rotation angle detection unit 210A, 210B, 210C Non-contact Sensors 220A, 220B, 220C Detected part 300 frames
Claims
1. A multiple lever mechanism comprising: a plurality of operating levers rotatably supported on the same rotating shaft; a rotation angle detection unit that detects the rotation angles of these operating levers; and a frame that supports the rotating shaft and houses the plurality of operating levers inside, wherein the rotation angle detection unit has a non-contact sensor and a detectable part that is detected by the non-contact sensor, the non-contact sensor and the detectable part are installed at a position away from the rotating shaft, the detectable part displaces circumferentially around the rotating shaft in response to the rotation of the operating lever, and the non-contact sensor does not displace regardless of the rotation of the operating lever.
2. 2. The multiple lever mechanism according to claim 1, wherein the non-contact sensor is a magnetic sensor, and the detected portion is a magnet magnetized in a height direction.
3. 2. The multiple lever mechanism according to claim 1, wherein the non-contact sensor is an optical sensor, and the detected portion is a light-emitting element.
4. 4. A multiple lever mechanism according to claim 1, 2 or 3, further comprising two switches which react in accordance with the direction of rotation of the operating lever in order to detect the direction of rotation of the operating lever.
5. 4. A multiple lever mechanism according to claim 1, 2 or 3, wherein a return mechanism for returning the operating lever to a neutral position is provided for each lever.
6. 4. The multiple lever mechanism according to claim 1, 2 or 3, further comprising a brake mechanism having a brake boss which rotates together with the operating lever and has a cylindrical portion coaxial with the rotation axis, and a pair of brake shoes which sandwich the cylindrical portion from both sides.
7. 4. The multiple lever mechanism according to claim 1, 2 or 3, wherein an operating lever fixing mechanism for fixing the operating lever in a neutral position is provided for each operating lever.
8. 7. The multiple lever mechanism according to claim 6, wherein an operating lever fixing mechanism for fixing the operating lever in the neutral position is provided for each operating lever.