JP2008228586A - Working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To constitute a working vehicle so as to perform its operation control with a proper timing. <P>SOLUTION: This working vehicle is equipped with a traveling distance-detecting means for detecting the traveling distance of a machine body, based on the number of rotations of its wheels, a steering angle-detecting means for detecting the steering angle of wheels, capable of freely performing its steering operation and an operation-controlling device performing the operation control, based on the traveling distances of the machine body detected by the traveling distance-detecting means and the steering angles of the wheels detected by the steering angle-detecting means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to operation control performed when turning a work vehicle.

Some passenger-type rice transplanters, which are examples of work vehicles, include an operation control unit that performs operation control when turning, as disclosed in Patent Document 1, for example.
In Patent Document 1, when the aircraft reaches the heel and the front wheel is steered, it is determined that turning at the heel has started (paragraph number [0038] of Patent Document 1), and the distance sensor (Patent Document) 1 in FIG. 3 (27), the detection (accumulation) of the travel distance of the body is started, and the seedling planting device is driven up automatically or manually (paragraph number [0039] of Patent Document 1).

Next, in the second half of the turn at the shore, when the mileage of the aircraft reaches the set distance, it is determined that the turn at the shore has ended (paragraph number [0042] of Patent Document 1), and seedling planting The device is automatically lowered (paragraph number [0044] in Patent Document 1). As a result, the number of operations performed by the driver when turning at the heel is reduced (the operation for lowering the seedling planting device by the elevating lever is not required), and the operability is improved.
In this case, in Patent Document 1, the rotational speed of the transmission shaft (34 in FIGS. 1 and 2 in Patent Document 1) for transmitting power to the wheels is detected by a distance sensor (27 in FIG. 3 in Patent Document 1). The travel distance of the airframe is detected (integrated) based on the number of rotations of the wheels.

JP 2002-233220 A JP 2001-86816 A

  When the front wheels are in a state of turning in the same turning direction from the start of turning to the end of turning, and turning in a semicircle, the distance traveled by the aircraft is the same as the turning of the aircraft. As shown in FIG. 1, when the traveling distance of the airframe reaches the set distance, it is determined that the turning at the heel has ended, and there is no problem even if the seedling planting device is driven downward.

  However, in a passenger type rice transplanter that is an example of a work vehicle, when turning at the shore, the front wheels are maintained at the same steering angle in the turning direction from the start of turning to the end of turning, and turn in a semicircle. For example, as disclosed in Patent Document 2, a riding type rice transplanter equipped with a seedling planting device having a large width such as an eight-row planting type is used to turn the first half of the turn at the shore. After performing (L1 in FIG. 8 of Patent Document 2), there may be a case where the vehicle travels a little straight (L2 in FIG. 8 of Patent Document 2) and turns in the latter half (L3 in FIG. 8 of Patent Document 2).

Thereby, as shown in FIG. 8 of Patent Document 2, when performing the first half turn, straight traveling, and the second half turn, it is only necessary to detect (accumulate) the travel distance of the aircraft as in Patent Document 1. Since the travel distance of the airframe is detected (accumulated) even during straight travel during the first and second half turns, if the straight travel during the first and second half turns becomes longer, the first half is not finished yet. In the straight traveling during the turn in the second half and the second half, the traveling distance of the airframe reaches the set distance, and it is determined that the turning at the end of the heel has ended, and the seedling planting device may be driven downward.
An object of the present invention is to configure a work vehicle so that operation control is performed at an appropriate timing.

[I]
(Constitution)
The first feature of the present invention is that the work vehicle is configured as follows.
A travel distance detecting means for detecting the travel distance of the airframe based on the number of rotations of the wheel and a steering angle detecting means for detecting the steering angle of the freely steerable wheel are provided. Operation control means for performing operation control is provided based on the travel distance of the airframe detected by the travel distance detection means and the steering angle of the wheels detected by the steering angle detection means.

(Function)
According to the first feature of the present invention, the operation control is not performed based only on the travel distance of the airframe, but is performed based on the travel distance of the airframe and the steering angle of the wheels.
In this case, for example, when the travel distance of the airframe is detected (integrated) in a state in which the wheel is steered in the turning direction, it can be determined that the turning angle of the airframe has increased by the travel distance of the airframe (turning is performed). It can be determined that it has progressed). On the contrary, for example, even if the travel distance of the airframe is detected (integrated) in a state where the wheel is steered to the straight traveling position, it can be determined that the airframe has just moved straight and that the turning angle of the airframe has not changed (turning has not been performed). It can be determined that it did not progress.)

  As a result, as described in [Problems to be Solved by the Invention], whether the turning angle of the airframe increases during the turn even when the first half turn, the straight running, and the second turn are performed. (In straight running during the first half and second half of the turn, it can be recognized that the turning angle of the aircraft has not changed) As a result, it is possible to perform operation control at an appropriate timing.

(The invention's effect)
According to the first feature of the present invention, in the work vehicle, the operation control is performed at an appropriate timing by considering the steering angle of the wheel in addition to the travel distance of the airframe, thereby improving the accuracy of the operation control. I was able to increase it.

[II]
(Constitution)
The second feature of the present invention is that the work vehicle of the first feature of the present invention is configured as follows.
An elevating mechanism that elevates and lowers the work device supported by the machine body is provided. Based on the travel distance of the airframe detected by the travel distance detection means and the steering angle of the wheels detected by the steering angle detection means, the lifting mechanism that is operated on the ascending side is operated on the descending side to operate the work device. An automatic lowering means for lowering is provided, and the automatic lowering means serves as an operation control means.

(Function)
According to the second feature of the present invention, the “action” described in the preceding item [I] is provided in the same manner as the first feature of the present invention, and in addition to this, the following “action” is provided.
According to the second feature of the present invention, as one of the operation control means described in the preceding item [I], an automatic lowering means (for example, when the travel distance of the aircraft from the start of turning reaches a set distance, it operates upward). The working mechanism is lowered by operating the elevating mechanism downward.

According to the second feature of the present invention, when the working device is automatically or manually lifted by the lifting mechanism and starts turning, the lifting and lowering that is actuated to the rising side based on the distance traveled by the aircraft and the steering angle of the wheels. The mechanism operates to the lowering side and the working device is lowered.
In this case, as described in [Problems to be Solved by the Invention], even if the first half turn, the straight running, and the second half turn are performed, whether or not the turning angle of the airframe increases during turning is changed. (In straight running during the first half and second half of the turn, it can be recognized that the turning angle of the aircraft has not changed) It becomes possible to recognize, so that the lifting mechanism that has actuated on the ascending side can act on the descending side at an appropriate timing so that the work device descends.

(The invention's effect)
According to the second feature of the present invention, the “effect of the invention” described in the preceding item [I] is provided in the same manner as the first feature of the present invention. In addition, the following “effect of the invention” is provided. ing.
According to the second feature of the present invention, when the automatic lowering means is adopted as one of the operation control means, the lifting mechanism operated on the rising side is considered by considering the steering angle of the wheel in addition to the travel distance of the aircraft. The work apparatus can be configured to move downward at an appropriate timing to move down, and the accuracy of the automatic lowering means can be improved.

[III]
(Constitution)
A third feature of the present invention resides in the following configuration in the first or second feature of the present invention.
A work clutch that can transmit and shut off power to the work device supported by the machine body is provided. Work clutch operation for operating the work clutch operated in the disconnected state to the transmission state based on the travel distance of the airframe detected by the travel distance detection means and the steering angle of the wheels detected by the steering angle detection means And a working clutch operating means as an operation control means.

(Function)
According to the third feature of the present invention, the “action” described in the preceding item [I] [II] is provided in the same manner as the first or second feature of the present invention. In addition, the following “action” is provided. It has.
According to the third feature of the present invention, as one of the operation control means described in the preceding item [I], a work clutch operation means (for example, when the distance traveled from the start of the turn reaches a set distance, the operation is performed in a disconnected state. Operating the operated clutch to the transmission state).

According to the third aspect of the present invention, when the work clutch is automatically or manually operated to be turned off to start turning, the work clutch is operated to be turned off based on the distance traveled by the aircraft and the steering angle of the wheel. The work clutch is operated in the transmission state.
In this case, as described in [Problems to be Solved by the Invention], even if the first half turn, the straight running, and the second half turn are performed, whether or not the turning angle of the airframe increases during turning is changed. (In straight running during the first half and second half of the turn, it can be recognized that the turning angle of the aircraft has not changed) As a result, the work clutch operated in the disconnected state can be operated in the transmission state at an appropriate timing.

(The invention's effect)
According to the third feature of the present invention, the “effect of the invention” described in the preceding paragraphs [I] and [II] is provided in the same manner as the first or second feature of the present invention. The effect of the invention is provided.
According to the third feature of the present invention, when the work clutch operating means is adopted as one of the operation control means, the work operated in the shut-off state by considering the steering angle of the wheel in addition to the travel distance of the airframe. The clutch can be configured to be operated in a transmission state at an appropriate timing, and the accuracy of the work clutch operating means can be improved.

[IV]
(Constitution)
A fourth feature of the present invention resides in the following configuration in any one of the work vehicles of the first to third features of the present invention.
A right side clutch capable of transmitting and interrupting power to the right wheel and a left side clutch capable of transmitting and interrupting power to the left wheel are provided. With the start of turning, the side clutch outside the turning is maintained in the transmission state, and the side clutch on the turning center side is operated in the disengaged state. The travel distance detecting means is configured to detect the travel distance of the airframe based on the rotation speed of the wheel on the turning center side.

(Function)
According to the 4th characteristic of this invention, it is equipped with "action" of previous clause [I]-[III] similarly to any one of the 1st-3rd characteristics of this invention, In addition to this, It has the following “actions”.
The work vehicle includes a right side clutch that can transmit and cut power to the right wheel, and a left side clutch that can transmit and cut power to the left wheel, and at the start of turning, There is a configuration in which the side clutch is maintained in the transmission state and the side clutch on the turning center side is operated in the disengaged state (see Patent Document 1). Thereby, at the time of turning, power is not transmitted to the wheel on the turning center side, the wheel on the turning center side freely rotates, and the wheel on the turning center side rotates according to the work place with turning, The work site is less likely to be roughened by the wheel on the turning center side.

  In this case, when power is transmitted to the wheel and the wheel is about to be driven to rotate, it is considered that the wheel may or may not slip depending on the relationship between the driving force of the wheel and the friction coefficient of the work site. . Conversely, if no power is transmitted to the wheel and the wheel rotates freely, it is the resistance from the work site based on the coefficient of friction of the work site that causes the wheel to rotate. Conceivable. Thereby, in the above-mentioned work vehicle, it is considered that the wheel on the turning center side (side clutch disengaged state side) rotates according to the work place with almost no slip accompanying the turning.

  According to the fourth feature of the present invention, since the travel distance detecting means is configured to detect (accumulate) the travel distance of the airframe based on the rotation speed of the wheel on the turning center side, it is possible to generate slip. By detecting (accumulating) the distance traveled by the small number of turning center side wheels (side clutch disengaged state), it is possible to detect the distance traveled by the aircraft while avoiding the occurrence of slips (while avoiding the effects of slips). (Integration) can be performed with high accuracy.

(The invention's effect)
According to the fourth feature of the present invention, the “effect of the invention” described in the preceding paragraphs [I] to [III] is provided similarly to any one of the first to third features of the present invention. In addition, the following “effects of the invention” are provided.
According to the fourth feature of the present invention, the travel distance of the airframe can be accurately detected (integrated) by the wheel on the turning center side (side clutch disengaged state side) that hardly generates slip. The operation control accuracy could be improved.
According to the fourth feature of the present invention, the mileage of the airframe can be accurately detected (integrated) by effectively using the right and left side clutches that are existing structures. It became advantageous in terms of simplification of the configuration.

[1]
As shown in FIG. 1, a link mechanism 3 is supported in a freely movable manner at the rear part of the machine body supported by right and left front wheels 1 (corresponding to wheels) and right and left rear wheels 2 (corresponding to wheels). , A single-acting hydraulic cylinder 4 (equivalent to an elevating mechanism) for driving the link mechanism 3 up and down is provided, and a seedling planting device 5 (equivalent to a working device) is supported at the rear of the link mechanism 3 to A riding rice transplanter, which is an example of a car, is configured. A paddy field generally has a mud or water layer formed on the lower hard cultivator G1, and the uppermost surface of the mud or water layer is a field surface G2, and the right and left front wheels 1, the right and left rear The wheel 2 travels in contact with the tiller G1.

  As shown in FIG. 1, the seedling planting device 5 includes four planting transmission cases 6, a rotary case 7 supported on the left and right of the rear portion of the planting transmission case 6, and rotatably supported at both ends of the rotary case 7. A pair of planting arms 8, a plurality of grounding floats 9, a seedling platform 10, and the like are provided and configured in an 8-row planting type. A hopper 14 for storing fertilizer and four feeding units 15 (corresponding to a working device) for storing fertilizer are provided on the rear side of the driver seat 13, and a blower 16 is provided on the lower side of the driver seat 13. . A groover 17 is provided on the ground float 9, and a hose 18 is connected across the feeding portion 15 and the groover 17.

  As shown in FIGS. 1 and 6, right and left markers 19 are provided on the right and left side portions of the seedling planting device 5, and a working posture in which an indicator is formed by touching the rice field G <b> 2 (see FIG. 1). , And a storage posture (see FIG. 6) that is separated upward from the field surface G2. The right and left markers 19 include an arm portion 19a supported by the seedling planting device 5 so as to be swingable up and down, and a rotating body 19b supported at the tip of the arm portion 19a so as to freely rotate. The electric motor 21 is provided to operate the right and left markers 19 to the working posture and the retracted posture, and the electric motor 21 is operated by the control device 23.

[2]
Next, the transmission system to the right and left front wheels 1 and the right and left rear wheels 2 will be described.
As shown in FIGS. 1 and 2, the power of the engine 31 is transmitted to the hydrostatic continuously variable transmission 33 and the transmission case 34 via the transmission belt 32, and the auxiliary transmission (not shown) inside the transmission case 34 is shown. ) To the right and left front wheels 1 through the front axle case 35. The power of the auxiliary transmission is transmitted to the transmission shaft 36, the input shaft 38 of the rear axle case 37, the bevel gear 38a fixed to the input shaft 38, the bevel gear 39a meshing with the bevel gear 38a, the transmission shaft 39 to which the bevel gear 39a is fixed, right and left Is transmitted to the right and left rear wheels 2 via the side clutch 40. The hydrostatic continuously variable transmission 33 is configured to be steplessly variable from the neutral position N to the forward side F and the reverse side R, and is hydrostatically driven by a shift lever 45 provided on the left side of the steering handle 20. The continuously variable transmission 33 is operated.

  As shown in FIGS. 2 and 3, a steering member 41 having a trapezoidal shape in plan view is swingably supported around the vertical axis P <b> 2 at the bottom of the mission case 34, and the steering member 41 is swung by the steering handle 20. The tie rod 42 is connected across the steering member 41 and the right and left front wheels 1. Thus, by operating the steering handle 20, the right and left front wheels 1 can be steered from the straight travel position A1 over the right and left steering limits A3.

  As shown in FIG. 4, the right and left side clutches 40 are a clutch case 40a that is externally fitted to the transmission shaft 39 so as to be relatively rotatable, and an operation that is externally fitted to the transmission shaft 39 so as to be integrally rotated and slidable by a spline structure. The member 40b, a plurality of friction plates 40c disposed between the clutch case 40a and the operation member 40b, and a spring 40d for urging the operation member 40b on the pressing side (transmission state side) of the friction plate 40c are configured. The right and left side clutches 40 are biased to the transmission state by the spring 40d.

  As shown in FIGS. 2 and 4, the right and left operation shafts 43 for sliding the operation members 40 b of the right and left side clutches 40 are supported downward on the rear axle case 37, The right and left operation rods 44 are connected to the right and left operation shafts 43 through the lower side of the front axle case 35. In the right and left operating rods 44, a connecting portion with the right and left operating shafts 43 is provided with a long hole 44 a as a versatility.

  As shown in FIGS. 2 and 4, when the right and left front wheels 1 are steered in the range of the rectilinear position A1 and the right and left set angles A2, the long holes 44a of the right and left operation rods 44a. As a result, the right and left side clutches 40 are operated in a transmission state. As a result, the aircraft moves forward (reverse) in a state where power is transmitted to the right and left front wheels 1 and the right and left rear wheels 2 (the transmission state of the right and left side clutches 40).

  As shown in FIGS. 2 and 4, when the right and left front wheels 1 are steered to the right steering limit A3 side beyond the right set angle A2, the slot 44a of the right operating rod 44 The right operating rod 44 is pulled beyond the range, the operating member 40b of the right side clutch 40 is slid by the right operating shaft 43, and the right side clutch 40 is operated in the disconnected state. The Thus, power is transmitted to the right and left front wheels 1 and the left rear wheel 2 (turning outside) (the transmission state of the left side clutch 40), and the right rear wheel 2 (turning center side) (the right side clutch). The airframe turns to the right in a state of free rotation (40 interruption state).

  As shown in FIGS. 2 and 4, when the right and left front wheels 1 are steered to the left steering limit A3 side beyond the left set angle A2, the slot 44a of the left operating rod 44 The left operating rod 44 is pulled beyond the range, and the operating member 40b of the left side clutch 40 is slid to the left in FIG. 4 by the left operating shaft 43, so that the left side clutch 40 is operated in the shut-off state. Accordingly, power is transmitted to the right and left front wheels 1 and the right rear wheel 2 (turning outside) (the transmission state of the right side clutch 40), and the left rear wheel 2 (turning center side) (left side clutch). The airframe turns to the left in a state of free rotation (40 interruption state).

[3]
Next, the transmission system to the seedling planting device 5 and the feeding unit 15 will be described.
As shown in FIGS. 1 and 6, in the mission case 34, the power branched from immediately before the auxiliary transmission is transferred to the seedling planting device 5 via the planting clutch 26 (corresponding to a working clutch) and the PTO shaft 25. The power that has been transmitted and branched off immediately before the auxiliary transmission is transmitted to the feeding portion 15 via the fertilizer clutch 27 (corresponding to a work clutch) and the drive rod 30, and is transmitted to the planting and fertilizer clutches 26 and 27. And the electric motor 28 operated to the interruption | blocking state is provided.

  As shown in FIGS. 1 and 6, when the planting clutch 26 is operated in the transmission state, the rotary case 7 is turned in the direction shown in FIG. It is rotated in the clockwise direction, and the planting arms 8 alternately take out the seedlings from the lower part of the seedling platform 10 and plant them on the rice field G2. When the planting clutch 26 is operated in the disconnected state, the reciprocating lateral feed drive of the seedling platform 10 and the rotational drive of the rotary case 7 are stopped.

  As shown in FIGS. 1 and 6, when the fertilizer clutch 27 is operated in the transmission state, the fertilizer is fed from the hopper 14 by a predetermined amount by the feeding unit 15, and the fertilizer is made through the hose 18 by the blower 16. The fertilizer is supplied to the rice field G2 through the groove generator 17. When the fertilizer application clutch 27 is operated in the disconnected state, the feeding unit 15 stops and the supply of fertilizer to the surface G2 stops.

[4]
Next, automatic elevation control of the seedling planting device 5 will be described.
As shown in FIG. 6, the rear portion of the center grounding float 9 is supported swingably up and down around the horizontal axis P <b> 1 of the seedling planting device 5, so that the height of the center grounding float 9 with respect to the seedling planting device 5 is high. A potentiometer 22 for detecting the height is provided, and a detection value of the potentiometer 22 is input to the control device 23. The center grounding float 9 follows the ground surface G2 as the aircraft progresses. By detecting the height of the central grounding float 9 with respect to the seedling planting device 5 based on the detection value of the potentiometer 22, the surface surface G2 ( The height from the center grounding float 9) to the seedling planting device 5 can be detected.

  As shown in FIG. 6, the hydraulic cylinder 4 is provided with a control valve 24 for supplying and discharging hydraulic oil, and the control valve 24 is operated by the control device 23. When hydraulic oil is supplied to the hydraulic cylinder 4 by the control valve 24, the hydraulic cylinder 4 is contracted to raise the seedling planting device 5, and when hydraulic oil is discharged from the hydraulic cylinder 4 by the control valve 24, the hydraulic pressure is increased. The cylinder 4 is extended and the seedling planting device 5 is lowered.

  As shown in FIG. 6, based on the height of the center grounding float 9 with respect to the seedling planting device 5 (height from the field G2 (center grounding float 9) to the seedling planting device 5), the seedling planting device 5 is maintained at the set height from the surface G2 (so that the detection value of the potentiometer 22 (the vertical distance between the potentiometer 22 and the center ground float 9) is maintained at the set value). The valve 24 is operated, the hydraulic cylinder 4 is expanded and contracted, and the seedling planting device 5 is automatically raised and lowered (automatic elevation control).

[5]
Next, the lifting lever 11 will be described.
As shown in FIGS. 1 and 6, an elevating lever 11 is provided on the right side of the driver's seat 13, and the elevating lever 11 is configured to be freely operated in an automatic position, a raised position, a neutral position, a lowered position, and a planting position. The operating position of the lift lever 11 is input to the control device 23. A potentiometer 29 that detects the vertical angle of the link mechanism 3 with respect to the airframe is provided, and the detection value of the potentiometer 29 is input to the control device 23.

  As shown in FIG. 6, when the elevating lever 11 is operated to the raised position, the neutral position, the lowered position, and the planting position (when the elevating lever 11 is not operated to the automatic position), it is described in [6] described later. The functions of the first and second raised positions U1 and U2 of the operation lever 12 and the functions of the first and second lowered positions D1 and D2 do not operate, only the functions of the right and left marker positions R and L of the operation lever 12. Operate.

  As shown in FIG. 6, when the elevating lever 11 is operated to the raised position, the automatic elevating control is stopped, the planting and fertilizing clutches 26 and 27 are operated to be disconnected by the electric motor 28, and the right and left are controlled by the electric motor 21. The control valve 23 is operated to the supply position by the control device 23, the hydraulic cylinder 4 is contracted and the seedling planting device 5 is raised. When the potentiometer 29 detects that the seedling planting device 5 has reached the upper limit position with the elevating lever 11 in the raised position, the control valve 24 is operated to the neutral position by the control device 23, and the hydraulic cylinder 4 automatically stops.

  As shown in FIG. 6, when the elevating lever 11 is operated to the lowered position, the automatic elevating control is stopped, the planting and fertilizing clutches 26 and 27 are operated to be disconnected by the electric motor 28, and the right and left are controlled by the electric motor 21. The control valve 24 is operated to the discharge position by the control device 23 in a state where the marker 19 is operated to the retracted posture, the hydraulic cylinder 4 is extended, and the seedling planting device 5 is lowered. When 9 touches the surface G2, the automatic lifting control is activated, and the seedling planting device 5 comes into contact with the surface G2 and stops.

  As shown in FIG. 6, when the elevating lever 11 is operated to the neutral position, the automatic elevating control is stopped, the planting and fertilizing clutches 26 and 27 are operated in the disconnected state by the electric motor 28, and the right and left are controlled by the electric motor 21. In the state where the marker 19 is operated to the retracted position, the control valve 24 is operated to the neutral position by the control device 23, and the hydraulic cylinder 4 is stopped. Thus, the seedling planting apparatus 5 can be raised and lowered to an arbitrary height and stopped by operating the elevating lever 11 to the raised position, the neutral position, and the lowered position.

  As shown in FIG. 6, when the elevating lever 11 is operated to the planting position, the automatic elevating control is activated in a state where the right and left markers 19 are operated to the retracted position by the electric motor 21, and the electric motor 28 is used for planting. The attachment and fertilization clutches 26 and 27 are operated to the transmission state. As a result, the rotary case 7 is rotationally driven as the seedling platform 10 is reciprocated laterally to the left and right, and the planting arms 8 alternately extract seedlings from the lower part of the seedling platform 10 and plant them on the rice field G2. The fertilizer is fed from the hopper 14 by a predetermined amount by the feeding unit 15, and the fertilizer is supplied to the groove forming device 17 through the hose 18 by the blower 16, and is supplied to the surface G <b> 2 through the groove forming device 17. The

[6]
Next, the operation lever 12 will be described.
As shown in FIGS. 1 and 6, an operation lever 12 is provided on the right lateral side below the steering handle 20, and the operation lever 12 extends laterally outward on the right side. The operation lever 12 has a first raised position U1, a second raised position U2, a lower first lowered position D1, a second lowered position D2, a rear right marker position R, and a front left marker position L from the neutral position N. It is configured to be operable in the cross direction and is biased to the neutral position N, and the operation position of the operation lever 12 is input to the control device 23.

As shown in FIG. 6, the function of the operation lever 12 operates as follows in the state where the elevating lever 11 is operated to the automatic position.
When the operating lever 12 is operated to the second ascending position U2 (when the operating lever 12 is operated to the second ascending position U2 and is operated to the neutral position N), the planting and fertilizing clutches 26 and 27 are operated to the disconnected state by the electric motor 28, The automatic elevation control is stopped, the right and left markers 19 are operated to the retracted position by the electric motor 21, the control valve 24 is operated to the supply position by the control device 23, and the hydraulic cylinder 4 is contracted to plant the seedlings. The device 5 is raised. When the potentiometer 29 detects that the seedling planting device 5 has reached the upper limit position, the control valve 24 is operated to the neutral position by the control device 23, and the hydraulic cylinder 4 automatically stops.

  As shown in FIG. 6, when the operation lever 12 is operated to the second lowered position D2 (operated to the second lowered position D2 and operated to the neutral position N), the control valve 24 is operated to the discharge position by the control device 23. Then, the hydraulic cylinder 4 extends and the seedling planting device 5 descends. When the center grounding float 9 contacts the surface G2, the automatic lifting control is activated and the seedling planting device 5 contacts the surface G2. And stop. After operating the operating lever 12 to the second lowered position D2 (after operating to the second lowered position D2 and operating to the neutral position N), when the operating lever 12 is operated again to the second lowered position D2, the automatic lifting control is performed. In the activated state, the planting and fertilizing clutches 26 and 27 are operated to the transmission state by the electric motor 28.

  For example, in the state where the automatic raising / lowering control is stopped, the planting and fertilizing clutches 26 and 27 are operated in the disconnected state by the electric motor 28, and the right and left markers 19 are operated in the retracted position by the electric motor 21 as shown in FIG. As shown, when the operation lever 12 is operated to the first raising position U1, the control valve 24 is operated to the supply position by the control device 23, the hydraulic cylinder 4 is contracted, and the seedling planting device 5 is raised. When the operating lever 12 is operated to the neutral position N, the control valve 24 is operated to the neutral position by the control device 23, and the raising of the seedling planting device 5 is stopped.

For example, in the state where the automatic raising / lowering control is stopped, the planting and fertilizing clutches 26 and 27 are operated in the disconnected state by the electric motor 28, and the right and left markers 19 are operated in the retracted position by the electric motor 21 as shown in FIG. As shown, when the operation lever 12 is operated to the first lowered position D1, the control valve 24 is operated to the discharge position by the control device 23, the hydraulic cylinder 4 is extended, and the seedling planting device 5 is lowered. When the operation lever 12 is operated to the neutral position N, the control valve 24 is operated to the neutral position by the control device 23, and the descent of the seedling planting device 5 is stopped.
Thus, the seedling planting device 5 can be raised and lowered only while the operation lever 12 is operated to the first raised and first lowered positions U1, D1. Can be raised and lowered to height.

  As shown in FIG. 6, when the operating lever 12 is operated to the right marker position R (operating to the right marker position R and operating to the neutral position N), the right marker 19 is operated to the acting posture by the electric motor 21. . When the operating lever 12 is operated to the left marker position L (operated to the left marker position L and operated to the neutral position N), the left marker 19 is operated to the operating posture by the electric motor 21.

[7]
Next, a structure related to operation control at the time of cornering will be described.
As shown in FIG. 6, the operation position of the shift lever 45 is input to the control device 23. As shown in FIGS. 2 and 3, a bracket 46 is fixed to the right lateral surface of the mission case 34, and a potentiometer 47 (corresponding to the steering angle detection means) is fixed to the bracket 46. 47a is extended downward, and the linkage rod 48 is connected through the lower side of the front axle case 35 across the steering member 41 and the detection arm 47a of the potentiometer 47. The potentiometer 47 can detect the steering angle of the right and left front wheels 1 (the range of the straight travel position A1 and the right and left steering limits A3) via the steering member 41. A value is input to the control device 23.

  As shown in FIGS. 2, 4, and 5, a ring member 49 having a large number of small irregularities on the outer periphery is externally fitted to the clutch case 40 a of the right and left side clutches 40, and the proximity sensor type right and left The left rotation speed sensor 50 is fixed to the upper portion of the rear axle case 37 so as to face the ring member 49, and the detection values of the right and left rotation speed sensors 50 are input to the control device 23. As a result, pulses are transmitted from the right and left rotational speed sensors 50 so as to correspond to the respective irregularities of the ring member 49, and the right and left rear wheels are generated by the pulses of the right and left rotational speed sensors 50. The number of rotations of 2 can be detected.

  In this case, as shown in FIGS. 4 and 5, the right and left rear wheels 2 are passed through the clutch case 40 a and the ring member 49 of the right and left side clutches 40 by the right and left rotational speed sensors 50. Since the rotational speed is detected, the right and left rear wheels are detected by the right and left rotational speed sensors 50 regardless of whether the right and left side clutches 40 are operated in the transmission state or in the disconnected state. The number of rotations of 2 can be detected.

  As shown in FIG. 6, travel distance detection means 51 that detects (accumulates) the first accumulated value C1 of the pulses of the right and left rotational speed sensors 50 and sets the travel distance of the airframe, and the right and left of the cultivation board G1 Slip rate detection means 52 for detecting the slip ratio of the rear wheel 2, automatic lowering means 53 (operation control means), work clutch operation means 54 (operation control means), and second integration of pulses of the right and left rotation speed sensors 50 A turning angle detecting means 55 that detects (integrates) the value C2 and detects the turning angle F1 of the airframe based on the detected value of the potentiometer 47 (the steering angle of the right and left front wheels 1) is provided in the control device 23. It has been.

[8]
Next, the first half of the operation control (rear travel distance L1 and front travel distance L2 in the first half) at the time of turning on the coast will be described with reference to FIGS.
In the riding type rice transplanter equipped with the eight-row type seedling planting device 5, as shown in FIG. 9, the rearward travel distance L1, the first half front travel distance L2, the first half turning stroke L3, the straight travel distance L4, There is a case where the second turning stroke L5 and the second half forward traveling stroke L6 are performed and the next planting stroke L02 is entered from one planting stroke L01.

  When one planting stroke L01 is completed, the driver performs planting (the seedling planting device 5 is lowered, the planting and fertilizing clutches 26 and 27 are transmitted, the right and left side clutches 40 are transmitted). State), the aircraft is advanced toward kite B, and when the front end of the aircraft reaches kite B (step S1), the shift lever 45 is operated to the neutral position N to stop the aircraft (step S2) (planting). Attached process L01).

  The driver stops the seedling planting device 5 with the elevating lever 11 or the operation lever 12 and raises it (the planting and fertilizing clutches 26 and 27 are disconnected, the seedling planting device 5 is raised) (steps S3 and S4). ) (Planting and fertilization clutch 26, 27 cut-off position E1), the shift lever 45 is operated to the reverse side R to move the aircraft backward (step S5), and when the aircraft moves backward by a desired travel distance, the shift lever 45 Is operated to the neutral position N to stop the aircraft (step S6) (rear travel distance L1).

  The driver operates the shift lever 45 to the forward side F to advance the aircraft (step S7). When the aircraft advances by a desired travel distance, the driver operates the steering handle 20 to move the right and left front wheels 1. When the right and left front wheels 1 are steered to the right (left) steering limit A3 side beyond the right (left) setting angle A2, the previous item [2 ], The side clutch 40 on the turning center side is operated in the disengaged state while the side clutch 40 outside the turning is maintained in the transmission state. It is detected by the potentiometer 47 that the right and left front wheels 1 are steered to the right (left) steering limit A3 side beyond the right (left) set angle A2 (step S8) (first half). Previous progress L2).

  In this case, after the driver operates the shift lever 45 to the reverse side R (step S5), the average value of the pulses of the right and left rotation speed sensors 50 (the rotation speed of the right and left rear wheels 2) is It is starting to be detected (integrated) as the first integrated value C1 (travel distance of the aircraft) in the control device 23, and the right and left front wheels 1 have reached the right (left) set angle A2 by the potentiometer 47. Until it is detected (steps S5 to S8), the average value of the pulses of the right and left rotational speed sensors 50 (the rotational speeds of the right and left rear wheels 2) is determined in the control device 23 by the first integrated value C1 ( It is detected (integrated) as the travel distance of the airframe (step S101) (travel distance detection means 51).

  In the control device 23, of the first integrated value C1 (travel distance of the aircraft) of the pulse, the first integrated value C1 (travel distance of the aircraft) in the rear travel distance L1 and the pulse in the first travel distance L2 in the first half. By seeing the difference from the first integrated value C1 (travel distance of the machine body), the cutoff position E2 of the side clutch 40 on the turning center side can be detected, and the cutoff positions of the planting and fertilizing clutches 26 and 27 are detected. The positional relationship between E1 and the cutoff position E2 of the side clutch 40 on the turning center side can be detected (step S9).

  If the right and left side clutches 40 are in the transmission state, there is no difference in the rotational speeds of the right and left rear wheels 2, but the right or left side clutch 40 is operated in the disengaged state at the rear travel stage L1. Assuming that there is a possibility that the steering handle 20 may be operated until it is done, the average value of the pulses of the right and left rotation speed sensors 50 (the rotation speed of the right and left rear wheels 2) is determined by the control device. 23, the first integrated value C1 (travel distance of the aircraft) is detected (integrated) (step S101).

[9]
Next, the middle half of the operation control at the time of turning on the coast (first half turning stroke L3, straight running stroke L4 and second half turning stroke L5) will be described with reference to FIGS.
When the control device 23 detects the positional relationship between the shut-off position E1 of the planting and fertilizing clutches 26 and 27 and the shut-off position E2 of the side clutch 40 on the turning center side (step S9), the turning at the heel is performed. The first set value CA1 and the second set value CA2 are set (step S10) when it is determined that it has been started (it is determined that the first half of the turning stroke L3 has been entered).

  By detecting the positional relationship between the shut-off position E1 of the planting and fertilizing clutches 26 and 27 and the shut-off position E2 of the side clutch 40 on the turning center side in the control device 23 (step S9), the side clutch on the turning center side is detected. After how many pulses are transmitted from 40 cut-off positions E2 (after reaching the distance traveled by the aircraft), when the planting and fertilizing clutches 26 and 27 are operated in the transmission state, the planting and fertilizing clutches It is detected whether the cut-off position E1 of 26 and 27 is coincident with the transmission position E5 of the planting and fertilizing clutches 26 and 27, and this detected value is set as the first set value CA1 (step S10).

  By detecting the positional relationship between the shut-off position E1 of the planting and fertilizing clutches 26 and 27 and the shut-off position E2 of the side clutch 40 on the turning center side in the control device 23 (step S9), the side clutch on the turning center side is detected. After how many pulses are transmitted from 40 cut-off positions E2 (after reaching the distance traveled by the aircraft), when the seedling planting device 5 is lowered, the proper timing is obtained without contacting the ridge B. Whether the seedling planting device 5 can be lowered is detected, and this detected value is set as the second set value CA2 (step S10).

The driver operates the steering handle 20 to cause the aircraft to travel (first half turning stroke L3, straight traveling stroke L4, and second half turning stroke L5).
In the control device 23, the pulse of the rotation speed sensor 50 on the turning center side (the rotation speed of the rear wheel 2 on the turning center side) from the breaking position E <b> 2 of the side clutch 40 on the turning center side It is detected (integrated) as an integrated value C1 (travel distance of the aircraft), and is added to the first integrated value C1 (travel distance of the aircraft) of the pulses in the rear travel distance L1 and the front travel distance L2 in the first half (step S102) (travel Distance detection means 51).
In the control device 23, a pulse of the rotation speed sensor 50 outside the turning (the rotation speed of the rear wheel 2 outside the turning) is newly generated from the breaking position E2 of the side clutch 40 on the turning center side. It is detected (integrated) as an integrated value C2 (step S103).

In the control device 23, the turning angle F1 of the airframe is detected (integrated) based on the second integrated value C2 of the pulse and the detected value of the potentiometer 47 (the steering angle of the right and left front wheels 1) (step S104). ) (Turning angle detecting means 55).
In this case, the second integrated value C2 of the pulse and the detected value of the potentiometer 47 (how much the current direction of the aircraft has changed with respect to the orientation of the aircraft at the cutoff position E2 of the side clutch 40 on the turning center side) And the detected value is detected (integrated) as the turning angle F1 of the airframe. If the turning angle F1 of the airframe is 90 degrees, the direction of the airframe is right sideways. If the turning angle F1 of the airframe is 180 degrees, the direction of the airframe is opposite. When the second integrated value C2 of the pulse is increased (when integrated) with the right and left front wheels 1 being steered in the turning direction, the turning angle of the aircraft is increased by the increment of the second integrated value C2 of the pulse. It is detected that F1 has increased. Conversely, even when the right and left front wheels 1 are steered to the straight-ahead position A1, even if the second integrated value C2 of the pulse increases (even if it is integrated), the aircraft only goes straight and the turning angle of the aircraft It is detected that F1 has not changed.

In the control device 23, the slip ratios of the right and left rear wheels 2 with respect to the tilling board G1 in the first and second half turning strokes L3 and L5 are detected (step S105) (slip ratio detection means 52).
In this case, depending on the relationship between the driving force of the rear wheel 2 on the outer side of the turn (the transmission state of the side clutch 40) and the friction coefficient of the tiller G1, slip occurs on the rear wheel 2 on the outer side of the turn (the transmission state of the side clutch 40). It is thought that it occurs or does not occur. If no power is transmitted to the rear wheel 2 on the turning center side (side clutch 40 is disconnected) and the rear wheel 2 on the turning center side (side clutch 40 is off) is free rotating, the turning center side ( Since the rotation of the rear wheel 2 of the side clutch 40 in the disengaged state is a resistance from the cultivator G1 based on the friction coefficient of the cultivator G1, the rear wheel 2 on the turning center side (in the disengaged state of the side clutch 40). It is considered that almost no slip occurs.

  Thereby, it is considered that the rear wheel 2 at the turning center side (the side clutch 40 is disengaged) in the turning strokes L3 and L5 in the first half and the second half rotates according to the tilling board G1 with almost no slip as the machine runs. Therefore, in the control device 23, the pulse (rotation speed) of the rotation speed sensor 50 on the turning center side (side clutch 40 disengaged state) and the pulse (rotation speed) of the rotation speed sensor 50 on the rotation outer side (transmission state of the side clutch 40) ( The slip ratio of the right and left rear wheels 2 with respect to the cultivator G1 is detected based on the ratio to the rotation speed).

For example, the pulse (number of revolutions) of the rotational speed sensor 50 on the outer side of the turn (the transmission state of the side clutch 40) is compared with the pulse (number of revolutions) of the rotational speed sensor 50 on the turning center side (side clutch 40 is disconnected). If the number of pulses (the number of revolutions) is within a predetermined number of pulses (revolutions) in consideration of the difference between the inner and outer wheels of the rear wheel 2 on the turning outer side and the turning center side, slip occurs on the rear wheel 2 on the outer turning side (the transmission state of the side clutch 40). It can be judged that it is not.
Conversely, the pulse (rotation speed) of the rotation speed sensor 50 on the rotation outer side (transmission state of the side clutch 40) is different from the pulse (rotation speed) of the rotation speed sensor 50 on the turning center side (side clutch 40 disengagement state). If the above-mentioned predetermined number of pulses (the number of revolutions) is exceeded, the pulse (number of revolutions) of the revolution number sensor 50 outside the turning (the transmission state of the side clutch 40) and the turning center side (the side clutch 40 is disconnected) ) To the pulse (rotation speed) of the rotation speed sensor 50, the slip ratios of the right and left rear wheels 2 with respect to the tilling board G1 are detected.

[10]
Next, the second half of the operation control (turning in the second half L5 and the forward travel L6 in the second half) during turning on the coast will be described with reference to FIGS.
When the driver operates the steering handle 20 to travel the aircraft, and the second integrated value C2 of the pulse reaches the second set value CA2 (step S11) (for example, in the middle of the second turning stroke L5), the control device At 23, the detected (integrated) turning angle F1 of the airframe is corrected based on the slip ratio (step S12). For example, if the slip ratio is large, it can be determined that the turning angle F1 of the airframe has not changed much even though the second integrated value C2 of the pulse is large. Therefore, the slip ratio is changed from the detected (integrated) turning angle F1 of the airframe. The correction value based on it is subtracted.

  Thereby, the second integrated value C2 of the pulse reaches the second set value CA2 (step S11), and the corrected turning angle F1 of the fuselage reaches the first set angle FA1 (for example, 150 degrees) ( In step S13), it is determined that the turning at the heel is normally performed, and the seedling planting device 5 in the ascending state automatically descends while maintaining the planting and fertilization clutches 26 and 27 in the disconnected state. (Step S14) (automatic lowering means 53).

  The airframe reaches the terminal position E4 of the second half of the turning stroke L5, and the driver operates the steering handle 20 to steer the right and left front wheels 1 to the straight travel position A1 side. The right and left front wheels 1 When the steering operation is performed to the straight travel position A1 side beyond the right (left) set angle A2, as described in the preceding item [2], the side clutch 40 outside the turning is maintained in the transmission state, The side clutch 40 on the turning center side is operated to the transmission state. It is detected by the potentiometer 47 that the right and left front wheels 1 are steered to the straight travel position A1 side beyond the right (left) set angle A2 (step S15) (the second half forward travel distance L5).

  In the control device 23, when the potentiometer 47 detects that the right and left front wheels 1 are steered to the straight travel position A1 side beyond the right (left) set angle A2 (step S15), the controller 23 immediately Is determined to have been completed (determined to have entered the forward travel L6 in the latter half). As a result, in the forward travel distance L6 in the latter half, the pulse of the rotation speed sensor 50 on the turning center side (the rotation speed of the rear wheel 2 on the turning center side) is corrected based on the slip ratio (step S16), but the corrected value is The pulse is added to the first integrated value C1 (travel distance of the aircraft) from the backward travel stroke L1 to the second half of the turning stroke L5 to obtain the first cumulative value C1 (travel distance of the aircraft) (step S106). (Travel distance detection means 51).

  In this case, for example, if the slip ratio is large, it can be determined that the airframe has not advanced much even though the first integrated value C1 of the pulse is large. Therefore, the slip ratio is determined from the first integrated value C1 of the detected (integrated) pulse. The correction value based on is subtracted and added (or the slip rate is added to the first integrated value C1 of the detected (integrated) pulse and added).

  When the first integrated value C1 of the pulse reaches the first set value CA1 (step S17), the control device 23 corrects the detected (integrated) turning angle F1 of the airframe based on the slip ratio (step S18). (Step S104). For example, if the slip ratio is large, it can be determined that the turning angle F1 of the airframe has not changed much even though the second integrated value C2 of the pulse is large. Therefore, the slip ratio is changed from the detected (integrated) turning angle F1 of the airframe. The correction value based on it is subtracted.

  As a result, the first integrated value C1 of the pulse has reached the first set value CA1 (step S17), and the corrected turning angle F1 of the fuselage has reached the second set angle FA2 (for example, 180 degrees) ( Step S19), it is determined that the turning at the shore is performed as usual, and it is determined that the seedling planting device 5 has reached the position E5 next to the blocking position E1 of the planting and fertilization clutches 26, 27. Then, the planting and fertilizing clutches 26 and 27 are operated in the transmission state (work clutch operating means 54) (step S20). Therefore, after this, the next planting process L02 is entered.

  In step S13, if the corrected turning angle F1 of the fuselage does not reach the first set angle FA1 (for example, 150 degrees), it is determined that the turning at the shore is not performed as usual, and thereafter The operations in steps S14 to S20 are not performed. Thereby, after this, the driver operates the elevating lever 11 or the operating lever 12 to perform the lowering of the seedling planting device 5, planting, and operation of the fertilization clutches 26 and 27 to the transmission state.

  In step S19, if the corrected turning angle F1 of the fuselage does not reach the second set angle FA2 (for example, 180 degrees), it is determined that the turning at the shore is not performed normally, and the subsequent steps The operation in step S20 is not performed. Thereby, after this, the driver operates the elevating lever 11 or the operating lever 12 to operate the planting and fertilizing clutches 26 and 27 to the transmission state.

[First Alternative Embodiment of the Invention]
In the turning angle detecting means 55 (step S104) of the above-mentioned [Best Mode for Carrying Out the Invention], the second integrated value C2 of the pulse and the detected value of the potentiometer 47 (the steering angle of the right and left front wheels 1). , Based on the first integrated value C1 of the pulse and the detected value of the potentiometer 47 (steering angle of the right and left front wheels 1), instead of detecting (integrating) the turning angle F1 of the aircraft, You may comprise so that the turning angle F1 of a body may be detected (integrated).

[Second Embodiment of the Invention]
The slip ratio detecting means 52 (step S105) of the above-mentioned [Best Mode for Carrying Out the Invention] [First Alternative Embodiment of the Invention] may be configured as follows.
(1)
The arm portion 19a of the right and left markers 19 shown in FIG. 6 includes a rotation speed sensor (not shown) for detecting the rotation speed of the rotating body 19b, and pulses of the rotation speed sensor 50 for the right and left rear wheels 2 are provided. By comparing (the number of revolutions) with the number of revolutions of the revolution number sensor of the right and left markers 19, the slip ratio of the right and left rear wheels 2 with respect to the tilling board G1 is detected. Thereby, in the planting strokes L01 and L02 in which the right or left marker 19 is operated to the acting posture, it is possible to detect the slip ratio of the right and left rear wheels 2 with respect to the tiller G1.

(2)
In the planting steps L01 and L02 shown in FIG. 9, the actual travel distance of the airframe is detected by GPS, and is compared with the pulses (rotations) of the rotation speed sensor 50 of the right and left rear wheels 2. The slip ratios of the right and left rear wheels 2 with respect to G1 are detected.
(3)
In the preceding paragraphs (1) and (2) and [Best Mode for Carrying Out the Invention] [First Another Embodiment of the Invention], the rotational speed sensor 50 is provided on the right and left front wheels 1.

[Third Another Embodiment of the Invention]
In the above-mentioned [Best Mode for Carrying Out the Invention] [First Different Mode of Carrying Out the Invention] [Second Another Mode of Carrying Out the Invention], as the operation control means, automatically when the turning at the end of the corner is completed Set the marker control means that the right or left marker 19 is operated to the action posture, or set the automatic deceleration means that automatically decelerates the traveling speed of the aircraft and turns it back to the original speed when turning on the coast May be.
In the present invention, an agricultural tractor that can be connected to a rotary tiller (equivalent to a working device) at the rear of the machine so that it can be driven up and down, and a cutting part (equivalent to an operating device) at the front of the machine can be driven up and down. It can also be applied to supported work vehicles such as combines.

Overall side view of riding rice transplanter Plan view showing steering operation system of right and left front wheels, transmission system to right and left front wheels, right and left rear wheels Side view near the steering member and potentiometer Transverse plan view near the left side clutch Vertical side view near the left side clutch The figure which shows the control system of a travel distance detection means, a slip ratio detection means, an automatic descent means, a work clutch operation means, and a turning angle detection means The figure which shows the flow of operation control at the time of turning at the shore The figure which shows the flow of operation control at the time of turning at the shore Plan view showing the state when turning on the shore

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Wheel 4 Lifting mechanism 5,15 Work device 26,27 Work clutch 40 Side clutch 47 Steering angle detection means 51 Travel distance detection means 53 Automatic descent means, operation control means 54 Work clutch operation means, operation control means

Claims (4)

A travel distance detecting means for detecting the travel distance of the airframe based on the rotational speed of the wheel, and a steering angle detecting means for detecting the steering angle of the freely steerable wheel;
A work vehicle comprising operation control means for performing operation control based on a travel distance of the airframe detected by the travel distance detection means and a steering angle of the wheels detected by the steering angle detection means. Equipped with an elevating mechanism that drives the working device supported by the machine up and down,
Based on the travel distance of the airframe detected by the travel distance detection means and the steering angle of the wheels detected by the steering angle detection means, the lifting mechanism operated on the ascending side is operated on the descending side. Equipped with automatic lowering means for lowering the working device,
The work vehicle according to claim 1, wherein the automatic lowering means is used as an operation control means. It has a working clutch that can transmit and cut power to the working device supported by the aircraft,
Based on the travel distance of the airframe detected by the travel distance detection means and the steering angle of the wheels detected by the steering angle detection means, the work clutch operated in the shut-off state is operated in the transmission state. With working clutch operating means,
The work vehicle according to claim 1 or 2, wherein the work clutch operation means is used as operation control means. It has a right side clutch that can transmit and cut power to the right wheel, and a left side clutch that can transmit and cut power to the left wheel,
As the turning starts, the side clutch outside the turning is maintained in a transmission state, and the side clutch on the turning center side is operated to be in a disconnected state,
The work vehicle according to any one of claims 1 to 3, wherein the travel distance detecting means is configured to detect a travel distance of the airframe based on a rotation speed of a wheel on a turning center side.

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