JP6341833B2 - Deadman device grip detection structure - Google Patents

Description

  The present invention relates to a grip detection structure of a deadman device used in a working machine that grips a handle and performs work.

  There are agricultural machines such as tillage machines and rolling machines that compact the ground as the working machines that hold the handle, and the rolling machines are known as the lama and the plate compactor. Yes. In a rammer, for example, a base having a compaction plate at the lower end, an engine provided on the top of the base, and a mechanism for converting the rotational force of the engine into a reciprocating motion of the base by a crank and transmitting it to the compaction plate via a spring (See Patent Document 1). In the above-mentioned rolling compactor, the work is performed while gripping the handle fixed to the base body as a vibrating body, and the main switch such as an ignition switch is located near the handle gripping portion so that it can be operated quickly when the operation is stopped. However, it is required to stop operation more reliably in an emergency.

  There is a deadman device as an emergency stop device for a working machine that grips and operates such a handle. As a deadman device, a lever-type switch is provided on the handle so that it can be operated normally while the handle is held together with the lever. What is said to be processed is known.

  However, the deadman device using a lever type switch has a problem that workability is poor because the lever provided on the handle is held together and the structure is complicated such as providing a switch driven by the lever. . Furthermore, even if the hand is released from the lever, the lever may be pressed by a part of the body.For example, the work machine may be tilted backward or backward due to some reason in the scene where there is a wall on the back of the worker. In this case, when an operator is sandwiched between the handle and the wall, the lever is operated and there is a problem that it cannot be stopped. In order to deal with such problems, for example, the handle of a power farm machine is made into a pipe shape, a light sensor composed of a light projecting element and a light receiving element is provided inside the part gripped by the hand, and a window provided in the gripping part is provided. When the light from the light projecting element is reflected by the lighted hand, it is received by the light receiving element, and the relay connected in series with the main switch is turned on in the light receiving state. The circuit is turned off to stop the engine (see Patent Document 2).

JP 2002-363915 A Japanese Utility Model Publication No. 1-81334

  However, in the above-mentioned Patent Document 2, since the optical sensor is disposed substantially at one place with respect to the circumferential direction of the gripping portion, the handle of the rammer that vibrates up and down when the structure is applied to the rammer, for example. It is difficult to always hold the camera in the same state, and there is a risk that the hand may be temporarily separated from the portion where the optical sensor is disposed. In that case, if the reflected light from the hand cannot be received sufficiently, there arises a disadvantage that the engine stops as in the case of releasing the hand. In addition, because of the optical sensor, if dirt is attached to the window, detection cannot be performed reliably, and there is a problem that it cannot be used in a poor environment such as a construction site.

  In view of the above background, the present invention provides a grip detection structure that can reliably perform a stop process of an engine with a simple structure by a deadman device used in a work machine that grips a handle and performs work. And

  In order to solve the above-mentioned problem, the present invention provides a deadman device grip detection structure provided in a work machine (1) provided with a handle (5), wherein the handle includes a main body (2) of the work machine. The rod-shaped body (5a) extends across the operator and is held by the worker, and the rod-shaped body has a surface (24a) continuous in the circumferential direction over the entire circumference. It has grip detection means (21, 23) for detecting grip of the operator inside, the grip detection means has a dead zone (a) on the side opposite to the main body side of the rod-shaped body, A range other than the dead zone is provided as the detection range (b).

  According to this configuration, even when the worker is sandwiched between the handle and the wall or the like in a scene where there is a wall or the like on the back of the worker, the grip detection means provided on the rod-like body gripped by the worker is the main body. Since there is a dead zone on the worker side opposite to the side, even if a part of the worker's body comes into contact with the rod-shaped body, it is not detected as a gripping force, and driving is performed by releasing the hand. Can be stopped. In addition, since the gripping state can be detected at any place except the operator side of the rod-like body, it can sufficiently cope with a change in the gripping position in a work machine that vibrates greatly like a runner. In addition, since the surface of the rod-like body is continuous in the circumferential direction over the entire circumference, the lever is not operated with anything other than a hand unlike the deadman device using the lever protruding from the handle. The gripping state can be detected using a pressure-sensitive sensor or a piezoelectric element, and a temperature sensor can also be used. In either case, the gripping state can be detected as an existing rod-shaped body that constitutes the gripping portion. It is possible, and the grip detection means can be provided with a simple structure.

  In the above invention, the gripping portion includes an elastic member (22) that is compressively deformed by the gripping force of the operator, and the grip detection means is provided on the inner peripheral side and the outer peripheral side of the elastic member. The elastic member may have a pair of electrodes (21, 23, 23a) that are electrically connected to each other by the compression deformation. According to this configuration, since the elastic member is compressed and deformed by the gripping force, the pair of electrodes provided on the inner and outer peripheral sides thereof are electrically connected to each other, so that the gripping state can be detected. A grip can be detected.

  Moreover, the said grip detection means is good to be provided in the annular member (25) divided | segmented into the circumferential direction. According to this configuration, the annular member can be fitted to the handle from the divided side and attached to the handle, and can be retrofitted to an existing work machine.

  The grip detection means may be provided at a plurality of locations. According to this configuration, since the grip detection means can be provided with a simple structure, it can be easily applied to a work machine such as a field cultivator that grips the handle with both hands so that it cannot be operated unless it is gripped with both hands. .

  As described above, according to the present invention, in a deadman device used in a work machine that performs work by gripping the handle, the worker grips even when the worker is sandwiched between the handle and the back wall or the like. Since the grip detection means provided on the rod-shaped body has a dead zone on the worker side that is opposite to the main body side, even if a part of the worker's body comes into contact with the rod-shaped body, it is detected as a gripping force. Therefore, the operation can be stopped by releasing the hand, and the engine stop process can be reliably performed with a simple structure.

Side view of a ramma to which the present invention is applied Schematic cross-sectional view showing a pressure-sensitive switch device provided in the handle gripping portion The figure corresponding to FIG. 2 which shows the pressure sensitive switch apparatus which can be retrofitted Top view of the main part of Ranma

  Embodiments of the present invention will be described below with reference to the drawings. In addition, when it demonstrates using upper and lower and front and back, it is set as the direction shown by the arrow of FIG.

  FIG. 1 is a side view of a runner 1 as an example of a work machine to which the present invention is applied. The rammer 1 is disposed above the base 2, the base 2 as the main body of the rammer 1, the rolling plate 3 attached to the lower end of the base 2, the engine 4 attached to the rear side of the upper end of the base 2. And a handle 5. The base body 2 is provided in a standing state inclined forward with respect to the main surface of the rolling plate 3, and the handle 5 may be formed by bending a pipe material and is orthogonal to the axis of the base body 2. It is formed in a rectangular shape having four sides of front, rear, left and right on the surface to be performed.

  Left and right mounting members 6 projecting in a rod shape are provided on the upper end portion of the base body 2 on the sides that are coaxial and opposite to each other, and left and right mounting plates that are bolted to the projecting end surfaces of the left and right mounting members 6, respectively. 7 extends upward, and left and right side portions of the handle 5 are fixed to upper end portions of the left and right mounting plates 7. Note that one end of the base plate 2 is coupled to the mounting plate 7, and the other end of the L-shaped reinforcing member 8 that extends backward and is bent upward is coupled to the left and right portions of the handle 5. Thus, the strength between the base 2 and the handle 5 is reinforced.

  The engine 4 may be an internal combustion engine or an electric motor, but will be described as an internal combustion engine in the present embodiment. The engine 4 is a manual starter type, and the recoil starter 11 is assembled to the engine 4. The recoil starter 11 may have a known structure, and also functions as a generator that generates power during operation.

  The engine 4 is attached in contact with the rear end surface of the upper end portion of the base 2. An output shaft 4a composed of one end of the crankshaft of the engine 4 protrudes into the base 2, and a crank mechanism that converts the rotational force of the output shaft 4a into reciprocating motion inside the base 2 and a crank mechanism. A mechanism for amplifying the converted reciprocating motion by a spring and transmitting the amplified reciprocating motion to the rolling plate 3 is provided. These mechanisms may be known ones, and illustration and description thereof are omitted.

  In addition, a grip 5a as a rod-shaped body that is gripped by an operator (not shown) is provided on the rear portion of the handle 5 that extends between the left and right sides. The operator works in a posture in which the grip 5a is gripped by being positioned on the side opposite to the base 2 side with respect to the grip 5a. The grip 5a extends across the base 2 and the operator in the left-right direction (front and back in the drawing), and the axis C of the grip 5a also extends in the same direction. In addition, the direction extended for crossing between the base | substrate 2 and the operator of the grip 5a is not restricted to the said left-right direction, The up-down direction may be sufficient.

  A main switch 12 is disposed in the vicinity of the grip 5 a of the engine 4, and a throttle operation lever 13 is disposed in the vicinity of the grip 5 a of the handle 5. The main switch 12 switches the power supply of the ramper 1 on and off, and may be a rotary switch, for example. The throttle operating lever 13 is connected to the throttle valve of the engine 4 via a cable. By operating the throttle operating lever 13, the engine speed can be increased or decreased within a predetermined range.

  When the work is performed by the runner 1, the main switch 12 is turned on and the throttle operation lever 13 is operated to adjust the engine speed to a predetermined value. As a result, the rotational force of the output shaft 4a is transmitted to the crank mechanism via the centrifugal clutch, and the ground 14 can be compacted by striking the rolling plate 3 up and down.

  FIG. 2 is a schematic cross-sectional view showing a pressure-sensitive switch device as grip detection means provided in a grip portion of a handle to which the present invention is applied. From the handle 5 side, the grip 5a of the handle 5 gripped by the operator during operation is provided with an inner electrode 21, an insulator 22 made of an elastic member, an outer electrode 23, and an insulating jacket 24, respectively. These members are laminated in this order so as to surround the outer peripheral surface of the member over the entire circumference. In addition, the surface 24a of the jacket 24 is formed in a cylindrical surface shape in the illustrated example as a surface continuous in the circumferential direction over the entire circumference of the grip 5a around the axis C of the grip 5a. In addition, the shape of the surface 24a does not need to be a perfect cylindrical surface, and there may be some unevenness | corrugations. For example, the grip 5a may be provided with a circumferential protrusion on a part thereof, which is a known shape, or may have an elliptical cross-sectional shape.

  The inner electrode 21 is formed in a cylindrical shape with a uniform thickness. On the other hand, the outer electrode 23 has a cylindrical portion concentric with the inner electrode 21, and is provided with inward protrusions 23a protruding toward the inner electrode 21 as contact points at three locations on the upper and lower sides and the rear side in the figure. ing. The insulator 22 is made of an elastic member that can be deformed inward in the radial direction when the operator grips the grip 5a with a gripping force during normal operation, and receives the inwardly protruding portion 23a and opens on the outer peripheral surface of the inner electrode 21. It is provided so that it may be pinched | interposed between both electrodes 21 * 23 except the hole to do.

  In addition, when a gap is generated between the protruding end surface of the inward projecting portion 23a and the outer peripheral surface of the inner electrode 21 when the grip 5a is not gripped, the gripping force is generated and the insulator 22 is compressed and deformed. The inward protrusion 23 a is set to be a gap that can contact the inner electrode 21.

  In the grip detection means configured as described above, one electrode (outer electrode 23) can be connected to the power supply line, and the other electrode (inner electrode 21) can be connected to the ground line. In the illustrated example, the outer electrode 23 is connected to the power line connected to the recoil starter 11 driven by the engine 4 via the main switch 12. For example, the stop circuit 15 is connected to the inner electrode 21. When the voltage is supplied, the stop circuit 15 enables the ignition system, for example, but may be controlled to stop the operation of the ignition system when the voltage is not supplied.

  During the operation, the insulator 22 is compressed inward in the radial direction by the gripping force for gripping the grip 5a, and accordingly, the electrodes 21 and 23 are deformed so as to be close to each other, and at least one inward projection 23a is inward. Abutting on the electrode 21, the electrodes 21 and 23 are brought into conduction. The stop circuit 15 enables the ignition system to operate the engine 4 as described above while detecting a voltage application state due to conduction between the electrodes 21 and 23, that is, a gripping state. On the other hand, when the hand is released from the grip 5a, the pressing force for compressing and deforming the insulator 22 by the gripping force disappears, so that the electrodes 21 and 23 become non-conductive, and the stop circuit 15 The engine 4 is stopped by the operation. Thereby, it is possible to configure a deadman device in which the engine 4 is stopped when the gripping force of the operator is weakened or the hand is completely separated from the grip 5a.

  Each inward projection 23a that constitutes a contact point for detecting the gripping state is disposed at an appropriate place other than the rear portion where the worker of the grip 5a is located in the working state. In the working state, the operator is located on the rear side with respect to the base body 2 of the runner 1, and the grip 5 a, which is the part of the handle 5 that is held by the operator, is located on the rear side with respect to the base body 2. Therefore, when the ramp 1 is tilted rearward for some reason, if there is a wall or the like on the back of the worker, the worker may be caught between the grip 5a of the handle 5 and the back wall or the like. is there.

  For example, when the grip detection range is provided on the rear side of the grip 5a, even if the worker releases his / her hand, a part of the worker's body sandwiched between the wall and the like abuts on the grip 5a. If the pressing force is erroneously detected as a gripping force, the engine may not stop. Even if it is not provided on the rear side of the grip 5a, in the case of the conventional lever type switch, the lever protrudes outward from the grip 5a. A part of the hook can be caught by the lever and operated.

  On the other hand, according to the present invention, the inward projection 23a constituting the grip detection means is not provided on the rear side portion of the grip 5a in the working state with respect to the base body 2. As a result, the worker is sandwiched between the handle 5 and the wall on the back surface, and even if a part of the worker's body presses the worker side range a which is the rear portion of the grip 5a. None of the inward projections 23 a comes into contact with the inner electrode 21. In this way, the worker side range a which is the side opposite to the base 2 of the grip 5a is provided as a dead zone of the gripping force detecting means. Therefore, even if the rammer 1 tilts backward and the worker is sandwiched between the grip 5a and the back wall or the like, the detection of the grip 5a other than the worker side range a by expanding his hand or the like. The engine 4 can be stopped by eliminating the gripping force with respect to the range b.

  Further, as shown in the illustrated example, there is no need to provide a portion that protrudes greatly outward from the surface 24a of the outer cover 24, which is the surface of the grip 5a, as in the lever of a lever type switch. There is no problem of making it. As described above, when the deadman device according to the present invention is applied to a work machine that performs work while gripping the handle 5 like the runner 1, the above-described remarkable effects can be achieved.

  In the illustrated example, the inward projections 23a are provided at three positions on the upper and lower sides and the rear side within the range of 180 degrees which is the front side of the grip 5a in the working state, but the position and number thereof are not limited. Further, only the pressing force with respect to the position of each inward projection 23a is not detected. For example, as shown in FIG. 2, the arc-shaped portion is deformed by the pressing force on the arc-shaped portion between the inward projections 23 a in the outer electrode 23, and the inward projection 23 a can be displaced radially inward accordingly. In addition, if the entire circumference of the grip 5a is within the detection range b other than the operator-side range a, any inward protrusion 23a is displaced by the pressing force applied by the gripping force to detect the gripping force. To get.

  Further, the gripping force detection means is not limited to the illustrated example, and for example, a known conductive rubber that becomes conductive when compressed may be provided instead of the insulator 22. By providing the sheet-like conductive rubber in the detection range b of the grip 5a, the gripping state with respect to the detection range b can be detected. Moreover, any pressure sensor that detects a gripping force equal to or greater than a predetermined value may be used. In addition, a capacitive proximity sensor that detects the proximity state of the human body can be used. In this case, the above-described detection of the grip 5a is performed by bending a flexible printed board on which a copper foil pattern as an electrode is formed. Provided in range b.

  In any case, the gripping force with respect to the worker side range a is set as the non-detection range, so that even if the worker is caught between the grip 5a and the back wall, the gripping force The engine 4 can be stopped when the power is lost.

  FIG. 3 is a view similar to FIG. 2 showing a pressure-sensitive switch device 25 that constitutes a gripping force detection means that can be retrofitted to the handle 5. In the figure, parts similar to those described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  The pressure-sensitive switch device 25 has a laminated structure similar to that shown in FIG. 2, but a part of the circumferential direction is divided in the circumferential direction, and in the illustrated example, the pressure-sensitive switch device 25 is composed of a cylindrical annular member having a C-shaped cross section as a whole. . The opening width d of the opening 25a serving as the C-shaped open portion is made smaller than the outer diameter of the handle 5, but is not affected by the elastic force of each material of the inner electrode 21, the insulator 22, the outer electrode 23, and the outer sheath 24. It may be arbitrary depending on the situation. For example, when the opening 25a is opened beyond the outer diameter of the handle 5, the opening width d that is simply cut may be substantially zero if the electrodes 21 and 23 are not damaged. . Further, the complementary member 26 is fitted into the opening 25a so that the surface 24a of the outer casing 24 is continuous in the circumferential direction over the entire circumference. Thereby, the grip 5a can be grasped without a sense of incongruity similarly to the said embodiment.

  According to the pressure-sensitive switch device 25 that can be retrofitted in this way, it can be retrofitted to various vibration machines that operate by gripping an existing handle, and can be easily replaced in the event of a failure. It will have. Note that the opening 25a is positioned on the rear side of the grip 5a in the mounting state of the ramper 1 of the present embodiment. Thereby, it can respond to said pinched state.

  FIG. 4 is a top view of the main part of the rammer 1. As shown in the drawing, the grips 5a that the operator grips with the left and right hands 31 and 32 are provided at appropriate positions on both the left and right sides at the portion of the handle 5 that extends in the left-right direction on the operator side. It has been. As described above, when the work 5 is gripped with the hands 31 and 32 at a distance from each other, the engine 4 may be stopped when it is detected that the grips 5a are not gripped at the same time. When the circuit of FIG. 2 is applied, the pair of electrodes 21 and 23 of both the grips 5a may be connected in series and connected to the stop circuit 15.

  Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to such embodiments and can be easily understood by those skilled in the art. It is possible to make appropriate changes without departing from For example, the outer electrode 23 is provided with the inward protrusion 23a, but the inner electrode 21 is also provided with an outward protrusion, or the inner peripheral surface of the outer electrode 23 is a cylindrical surface and the outer electrode 23 is provided with an outward protrusion. May be. In addition, all the components shown in the above embodiment are not necessarily essential, and can be appropriately selected without departing from the gist of the present invention. For example, if the inner electrode 21 is provided, but the handle 5 is conductive, the handle 5 can be used instead of the inner electrode 21. As a result, the grip detection means can have a simpler structure. Moreover, although the said embodiment demonstrated the rammer 1, application of this invention is not restricted to the rammer 1, It can apply also to a plate compactor, a lawn mower, a tillage machine, etc.

1 Ranma (work machine)
2 Base body
5 Handle 5a Grip (bar-shaped body)
21 Inner electrode 22 Insulator 23 Outer electrode 23a Inward projecting portion 24a Surface 25 Pressure sensitive switch device a Worker side range (dead zone)
b Detection range

Claims (4)

Detecting gripping of a deadman device that is provided in a work machine having a handle and an engine and that makes the engine operable while gripping the handle is detected and stops the engine when gripping of the handle is no longer detected Structure,
Provided in the handle, extending transversely between the body and the operator of the working machine, comprising a rod-shaped body in which the operator grips,
The rod-shaped body has a surface continuous in the circumferential direction over the entire circumference, and has a grip detection means for detecting gripping of the operator inside,
Said grip detection means, wherein said form is opposite the operator side range from the main body side of the surface of the rod-shaped body, and the range of the dead band is not detected gripping of the operator, the range outside the range of the dead zone in the surface And a detection range for detecting gripping by the operator . A gripping detection structure for a deadman device. The rod-shaped body, has a total circumferential or peripheral direction of the C-shaped cross-section which is divided in a circumferential direction of said surface so as to form a portion of the surface, an annular member mounted on the outer peripheral side of the handle ,
Grip detection structure of dead man's switch according to claim 1, wherein said gripping detecting means, characterized in that provided on the annular member. The rod-shaped body, an elastic member to compressive deformation by the gripping force of the worker,
It said grip detection means is provided on the inner peripheral side and the outer peripheral side of the elastic member, according to claim 1 or claim wherein the elastic member is characterized by having a pair of electrodes electrically connected to each other by the compression deformation 3. A grip detection structure for a dead man device according to 2 . 4. The deadman device grip detection structure according to claim 3 , wherein contact points of the pair of electrodes are provided at a plurality of locations in the circumferential direction of the rod-shaped body .

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