JP4437979B2 - snowblower - Google Patents

Description

  The present invention relates to a snowplow having a self-propelled machine body equipped with an engine-driven snow removal working unit.

Some snowplows equipped with an engine-driven snow removal unit, such as an auger type snowplow, increase the load on the snowplow operation unit depending on the running speed and work conditions. The auger type snow remover is a working machine that scrapes snow with a front auger while moving forward to remove snow. As the running speed increases, the amount of snow removed by the auger also increases. As a result, the load on the auger increases. As such an auger type snow removal machine, various types are known (for example, refer to Patent Document 1).
Japanese Utility Model Publication No. 3-32617

A conventional auger type snowplow shown in Patent Document 1 will be described with reference to FIG. FIGS. 13A and 13B are configuration diagrams of a conventional auger type snowplow. FIG. 13A shows an auger type snowplow viewed from the side. FIG. 13B schematically shows the auger type snowplow. Show.
The conventional auger type snow removal machine 100 is configured such that a machine body 102 having a snow removal operation unit 101 is caused to travel by a traveling unit 103, and the snow removal operation unit 101 and the traveling unit 103 are driven by an engine 104. The snow removal working unit 101 includes an auger 111, a blower 112 and a shooter 113.

  According to the auger type snowplow 100, the rotational speed of the engine 104 is detected by the speed sensor 121, and the torque transmitted from the engine 104 to the auger 111 and the blower 112 is detected by the torque sensor 122. Based on this, the control unit 123 can estimate the snow quality and the amount of snow that is being removed.

  The control unit 123 controls the speed of the traveling unit 103, the auger 111, and the blower 112 based on the estimation result. More specifically, when the control unit 123 estimates that the snow quality is ice and snow and the amount of snow is small, the control unit 123 decreases the speed of the traveling unit 103 and increases the speed of the auger 111 and the blower 112, When it is estimated that the snow quality is normal (soft snow or the like) and the amount of snow is large, the speed of the traveling unit 103, the auger 111 and the blower 112 is decreased.

  By the way, since the snow removal work is performed at a low temperature, it takes a relatively long time until the warm-up operation (warm-up) is completed after the engine 104 is started. Until that is done, the worker will continue to wait without snow removal, which is troublesome. In order for the operator to manually warm up, the choke valve is first throttled and then gradually opened according to the warm-up state.

Since this work is troublesome, it is conceivable to employ an automatic choke. The automatic choke is a device that automatically opens and closes the choke valve according to the temperature state of the engine, and is also called an auto choke. That is, what is necessary is just to set it as the structure which adjusts each opening degree of an engine choke valve and a throttle valve with an electronic governor, and various such apparatuses are known.
For example, various types of working machines equipped with an engine that adjusts the opening of a throttle valve with an electronic governor are known (see, for example, Patent Document 2).
Japanese Patent No. 2832610

  The conventional technique shown in Patent Document 2 is that an electronic governor type throttle valve is provided in an engine mounted on a rice transplanter or a management work machine. What is necessary is just to attach an automatic choke to the engine of this working machine.

Returning to FIG. 13, the description will be continued. Here, consider a case where an electronic governor that adjusts the opening degree of the choke valve and the throttle valve is employed in the engine 104 of the conventional auger type snowplow 100. The warm-up operation is performed with the choke squeezed, but if the snow removal operation is started while the auger type snow remover 100 is moved forward in this state, the burden on the engine 104 is large.
In particular, when the traveling unit 103 is separated from the driving method by the engine 104 and is driven by an electric motor, the auger type snowplow 100 is moved forward although the engine 104 is in a warm-up operation. The tendency is strong.

The performance of a general snowplow when the traveling unit 103 is an electric motor drive system will be described with reference to FIG.
FIG. 14 is a diagram for explaining the performance of a conventional snowplow. The horizontal axis represents elapsed time, the left vertical axis represents the throttle valve opening Str, and the right vertical axis represents the choke valve opening Cr and the electric motor. The actual performance of the snowplow is shown as the actual speed Tr.

When the time when the engine is started is t1, and the time when the warm-up operation is completed is t2, the opening degree Cr of the choke valve is 0% at t1, and 100% at t2. That is, the opening degree Cr of the choke valve gradually increases from 0% to 100% according to the warm-up state.
Almost simultaneously with the start of the engine, when the snow removal working part is driven by the engine while the traveling part is advanced by the electric motor, the load on the engine is large, so the opening degree Str of the throttle valve increases rapidly. . That is, the throttle valve opening Str is larger than necessary.

  In the case where the actual speed Tr of the electric motor decreases with respect to the increase in the throttle valve opening Str, the actual speed Tr of the electric motor rapidly decreases as the throttle valve opening Str increases rapidly. For this reason, the snow removal work of the snow remover does not proceed. This makes no sense to start the snow removal work quickly while the engine is warming up. There is room for improvement to improve snow removal workability.

  This invention makes it a subject to provide the technique which can improve the workability | operativity of the snow removal machine provided with the engine drive type snow removal operation part in the body which can be self-propelled with an electric motor.

The invention according to claim 1 includes an engine that drives a snow removal working unit such as an auger provided in the fuselage, an electronic governor that adjusts the opening degree of the choke valve and throttle valve of the engine, and a travel unit that travels the fuselage. An electric motor for driving the electronic governor, a control unit for controlling the traveling speed by relating the electric motor to the electronic governor, and a target speed adjusting unit for instructing the target speed of the electric motor to the control unit, A snowblower with
When the start condition that the choke valve is being driven is satisfied, the control unit reduces the rate at which the traveling speed decreases with respect to the increase in the opening of the throttle valve, compared to when the choke valve is stopped. It is the structure which controls.

The invention according to claim 2 is to execute the control unit according to claim 1 when the start condition is satisfied.
A map used when starting the engine, wherein the deceleration correction coefficient of the electric motor decreases as the opening of the throttle valve increases, and the deceleration correction coefficient when fully open is greater than 0. From the step of obtaining a deceleration correction coefficient of the electric motor corresponding to the opening of the throttle valve at that time,
Correcting by multiplying the deceleration correction coefficient by the target speed;
Controlling the speed of the electric motor at the corrected target speed;
It is provided with.

The invention according to claim 3 is to be executed when the control unit satisfies the start condition in claim 1.
An electric map corresponding to the choke valve opening at that time, based on an initial correction map having a characteristic that the initial correction coefficient of the electric motor increases as the choke valve opening increases. Obtaining an initial correction factor for the motor;
This map is used after engine startup is complete, and corresponds to the throttle valve opening at that time from the normal correction map that has the characteristic that the deceleration correction coefficient of the electric motor decreases as the throttle valve opening increases. Obtaining a deceleration correction coefficient of the electric motor to perform,
Correcting by multiplying the target speed by the reciprocal of the initial correction coefficient and the deceleration correction coefficient;
Controlling the speed of the electric motor at the corrected target speed;
It is provided with.

  According to a fourth aspect of the present invention, in the first, second, or third aspect, the control unit includes a condition that the traveling unit is performing a forward operation and a condition that the snow removal working unit is performing a snow removing operation. Only when two conditions are satisfied, the rate at which the traveling speed decreases with respect to the increase in the throttle valve opening is controlled to be smaller than when the choke valve is stopped. To do.

In the invention according to claim 1, in the engine start state in which the choke valve is driven, control is performed such that the rate at which the traveling speed decreases with respect to the increase in the opening of the throttle valve is smaller than after the start is completed.
Almost simultaneously with the starting of the engine, when the snow removal working part is driven by the engine while the traveling part is advanced by the electric motor, the load on the engine is large, and the opening of the throttle valve increases rapidly.
On the other hand, in the invention according to claim 1, even if the opening degree of the throttle valve increases rapidly, the speed of the electric motor is decreased relatively slowly. For this reason, the speed of the snow blower also decreases relatively slowly. As a result, the snow removal work by the snow removal working unit can be promoted. In this way, the snow removal workability during the warm-up operation of the engine is enhanced, so that the snow removal workability of the snow removal machine can be further enhanced.

In the invention according to claim 2, the deceleration correction coefficient of the electric motor decreases as the throttle valve opening increases, and a start-up correction map having a characteristic that the deceleration correction coefficient when fully opened is greater than 0 is adopted. The deceleration correction coefficient of the electric motor corresponding to the opening of the throttle valve at that time is obtained. Since the speed of the electric motor is controlled based on the target speed corrected by the deceleration correction coefficient, the speed of the electric motor does not become the lowest even if the throttle valve is fully opened. In addition, since the deceleration correction coefficient for full opening is set to be greater than 0, the rate at which the deceleration correction coefficient decreases as the throttle valve opening increases can be reduced accordingly. The fully open deceleration correction coefficient may be set to an optimum value in consideration of the characteristics of the snowplow and the engine.
For this reason, even if the opening degree of the throttle valve increases rapidly, the speed of the electric motor decreases relatively slowly.

  Furthermore, since the deceleration correction coefficient at that time is obtained from the start time correction map, the deceleration correction coefficient can be obtained very quickly. Based on the target speed corrected with this deceleration correction coefficient, the electric motor Can be controlled more quickly. Therefore, when the engine is started, the responsiveness (response) of the speed change of the electric motor to the load on the engine is good. For this reason, the snow removal workability of the snow remover can be further enhanced.

In the invention according to claim 3, the initial correction map having a characteristic that the initial correction coefficient of the electric motor increases as the opening of the choke valve increases, and the deceleration of the electric motor as the opening of the throttle valve increases. A normal correction map having a characteristic that the correction coefficient decreases is prepared.
When the engine is started, the initial correction coefficient of the electric motor corresponding to the current choke valve opening is obtained from the initial correction map, and the electric motor corresponding to the current throttle valve opening is determined from the normal correction map. Thus, the target speed can be corrected very quickly by multiplying the target speed of the electric motor by the reciprocal of the initial correction coefficient and the deceleration correction coefficient. Based on the corrected target speed, the speed of the electric motor can be controlled more quickly.

When the engine is started, the opening of the choke valve gradually increases according to the warm-up state. On the other hand, almost simultaneously with starting the engine, if the snow removal working part is driven by the engine while the traveling part is advanced by the electric motor, the load on the engine is large, so the opening of the throttle valve increases rapidly. To do.
That is, when the snow removal work is performed almost simultaneously with the start of the engine, (1) when the engine is hardly warmed up, the opening of the choke valve is small and the opening of the throttle valve is large. (2) As the warm-up progresses, the opening of the choke valve increases and the opening of the throttle valve decreases.

  In the invention according to claim 3, paying attention to this point, the correction is made not only by multiplying the target speed of the electric motor by the deceleration correction coefficient but also by the reciprocal of the initial correction coefficient. In this way, the speed of the electric motor can be controlled more precisely and more quickly. Therefore, when the engine is started, the responsiveness (response) of the speed change of the electric motor to the load on the engine is good. For this reason, the snow removal workability of the snow remover can be further enhanced.

In the invention according to claim 4, in the engine starting state where the choke valve is driven, the opening degree of the throttle valve is only when the snow removal machine is removing snow while moving forward, that is, only when removing snow. The rate at which the traveling speed decreases with respect to the increase in speed is reduced.
When the snow removal work is not being performed, the snow removal machine is only moved, so the load associated with snow removal is not applied to the engine. In the invention which concerns on Claim 4, since a driving speed can be freely set irrespective of the state of an engine, the mobility of a snowplow improves.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. “Front”, “Rear”, “Left”, “Right”, “Up”, “Down” follow the direction viewed from the operator, Fr is front, Rr is rear, Le is left, Ri is right Indicates.
FIG. 1 is a side view of a snow removal machine (work machine) according to the present invention. FIG. 2 is a schematic plan view and control system diagram of the snowplow according to the present invention.

  As shown in FIGS. 1 and 2, the snowplow 10 includes a vehicle body that includes an auger-type working unit 13 and an engine 14 that drives the working unit 13 on a traveling frame 12 that includes left and right traveling units 11L and 11R. The rear part of the frame 15 is mounted so that it can swing up and down, the front part of the vehicle body frame 15 is moved up and down by the lift drive mechanism 16, and the left and right operation handles 17L and 17R are extended from the rear part of the traveling frame 12 to the upper rear part. The operation handles 17L and 17R are provided with grips 18L and 18R at the tips of the operation handles 17L and 17R.

  Such a snow removal machine 10 is said to be an auger type snow removal machine. Hereinafter, the working unit 13 is referred to as a snow removal working unit 13. An operator can operate the snow removal machine 10 with the operation handles 17L and 17R while walking with the snow removal machine 10.

The combined structure of the traveling frame 12 and the vehicle body frame 15 forms an airframe 19. The traveling frame 12 includes left and right electric motors 21L and 21R that drive the traveling units 11L and 11R. The left and right traveling units 11L and 11R include left and right crawler belts 22L and 22R, left and right driving wheels 23L and 23R disposed at the rear as traveling wheels, and left and right rolling wheels 24L and 24R disposed at the front. .
The left crawler belt 22L can be driven via the left driving wheel 23L by the driving force of the left electric motor 21L. The right crawler belt 22R can be driven via the right drive wheel 23R by the driving force of the right electric motor 21R.

  The snow removal working unit 13 includes an auger housing 25, a blower case 26 integrated with the back surface of the auger housing 25, an auger 27 provided in the auger housing 25, a blower 28 provided in the blower case 26, and a shooter 29.

As shown in FIG. 1, the engine 14 is a snow removal drive source that drives the snow removal working unit 13 via an electromagnetic clutch 31 and a transmission mechanism 32.
The transmission mechanism 32 is a belt-type transmission mechanism that transmits power from the electromagnetic clutch 31 attached to the crankshaft 14 a of the engine 14 to the auger transmission shaft 33 using a belt. The power of the engine 14 is transmitted to the auger 27 and the blower 28 through a path of the crankshaft 14 a → the electromagnetic clutch 31 → the transmission mechanism 32 → the auger transmission shaft 33. The snow collected by the auger 27 can be blown away by the blower 28 via the shooter 29.
The auger housing 25 includes a scraper 35 and left and right sleds 36L and 36R at the rear lower end.

  The elevating drive mechanism 16 is an actuator in which a piston can advance and retreat from a cylinder. This actuator is a type of electric hydraulic cylinder in which a piston is extended and contracted by hydraulic pressure generated from a hydraulic pump (not shown) by an electric motor 16a (see FIG. 2). The electric motor 16 a is an elevating drive source that is integrated into the side of the cylinder of the elevating drive mechanism 16.

Such a snowplow 10 has a configuration in which the auger housing 25 and the blower case 26 are attached to the traveling frame 12 so as to be able to roll, and the auger housing 25 is rolled left and right (rolled) by a rolling drive mechanism 38.
More specifically, the auger transmission shaft 33 extending in the front-rear direction is rotatably supported by the auger housing 25 and the blower case 26, and the blower case 26 is attached to the front end portion of the vehicle body frame 15 so as to be rotatable left and right (rollable). is there.

  As described above, the traveling frame 12 has a configuration in which the vehicle body frame 15 is attached. For this reason, the auger housing 25 and the blower case 26 are attached to the traveling frame 12 so as to be able to roll. As a result, the auger housing 25 can be lifted and lowered with respect to the traveling frame 12.

  The rolling drive mechanism 38 is an actuator capable of moving a piston back and forth from a cylinder. This actuator is a type of electric hydraulic cylinder in which a piston is extended and contracted by hydraulic pressure generated from a hydraulic pump (not shown) by an electric motor 38a (see FIG. 2). The electric motor 38 a is a rolling drive source that is integrated into the side of the cylinder of the rolling drive mechanism 38.

  By the way, an operation unit 40, a control unit 61, and a battery 62 are arranged between the left and right operation handles 17L and 17R. Hereinafter, the operation unit 40 will be described.

  FIG. 3 is a perspective view of the operation unit according to the present invention. FIG. 4 is a plan view of the operation unit according to the present invention. 3 and 4, the operation unit 40 includes an operation box 41 provided between the left and right operation handles 17L and 17R, a travel preparation lever 42 provided on the left operation handle 17L near the grip 18L, and a left Turning control lever 43L and a right turning operation lever 43R attached to the right operation handle 17R in the vicinity of the grip 18R.

  The travel preparation lever 42 is a travel preparation member that acts on the switch 42a (see FIG. 2), and the switch 42a is turned off when the free spring shown in FIG. If the travel preparation lever 42 is grasped with the operator's left hand and lowered to the grip 18L side, the switch 42a is turned on.

The left and right turning operation levers 43L and 43R are turning operation members that are respectively operated by the hands holding the left and right grips 18L and 18R, and are mechanisms that act on the corresponding turning switches 43La and 43Ra (see FIG. 2).
When these left and right turning operation levers 43L and 43R are brought into a free state shown in the figure by the pulling action of the return spring, the turning switches 43La and 43Ra are turned off. If the operator turns the left turning lever 43L with the left hand and raises it to the grip 18L side, the left turning switch 43La is turned on. The same applies to the right turning switch 43Ra. In this way, whether or not the left and right turning operation levers 43L and 43R are being gripped can be detected by the turning switches 43La and 43Ra.

Referring to FIG. 2 as well, the operation box 41 includes a main switch 44 and an auger switch 45 (also referred to as “clutch operation switch 45”) on the back surface 41a (worker side surface).
The engine 14 can be started by turning the main switch 44 on. The auger switch 45 is a manual switch that switches the electromagnetic clutch 31 on and off, and includes, for example, a push button switch.

Further, the operation box 41 has a mode changeover switch 51, a throttle lever 52, a direction speed lever 53, a reset switch 54, an auger housing posture operation lever 55 and a shooter operation lever 56 arranged on the upper surface 41b in this order from the left side to the right side. , Which is provided.
More specifically, a directional speed lever 53 is arranged on the upper surface 41b of the operation box 41 on the left side of the vehicle width center CL, and a reset switch 54 is arranged on the right side of the vehicle width center CL.

The mode changeover switch 51 is a manual changeover switch that switches the travel control mode in the control unit 61, and is formed of, for example, a rotary switch. It is possible to switch to the first control position P1, the second control position P2, and the third control position P3 by turning the knob 51a counterclockwise. When switching to each of these positions P1, P2, P3, the mode changeover switch 51 issues a corresponding switch signal.
The first control position P1 is a switch position for causing the control unit 61 to perform control in the “first control mode”. The second control position P2 is a switch position for causing the control unit 61 to perform control in the “second control mode”. The third control position P3 is a switch position for causing the control unit 61 to perform control in the “third control mode”.

  The first control mode is a so-called manual mode in which control is performed manually based on the rotational speed of the engine 14. The second control mode is a so-called power mode in which the traveling speed is controlled to be gradually decreased with respect to the increase amount of the opening degree of the throttle valve 71. The third control mode is a so-called auto mode (automatic mode) in which the traveling speed is controlled so as to decrease more greatly than in the second control mode with respect to the increase amount of the opening degree of the throttle valve 71. . In the second and third control modes, the travel speed may be controlled based on the rotational speed of the engine 14 instead of the opening of the throttle valve 71.

As described above, the load control mode of the control unit 61 is changed to (1) a first manual operation mode used by an advanced user accustomed to work, and (2) a semi-automatic type used by an intermediate worker accustomed to some degree. This mode is set to three modes: a second control mode and (3) an automatic third control mode used by an unfamiliar beginner.
By appropriately selecting these modes, one snowblower 10 can be easily used from beginners to advanced workers in a work mode that is optimal for them.

  The throttle lever 52 is an operating member for controlling the opening and closing of the throttle valve 71 by controlling a control motor 72 of an electronic governor (also referred to as an electric governor). The voltage can be reciprocated in the front-rear direction, and a voltage corresponding to the position is generated by the potentiometer 52a. When the throttle lever 52 is tilted in the direction of the arrow De, the throttle valve 71 can be closed until it is fully closed, and when the throttle lever 52 is tilted in the direction of the arrow In, the throttle valve 71 can be opened until it is fully opened. As a result, the rotational speed of the engine 14 can be adjusted.

  The direction speed lever 53 is an operation member for controlling the rotation of the electric motors 21L and 21R, and details thereof will be described later (see FIG. 5).

  The reset switch 54 (auger original position automatic return switch 54) is a manual switch for returning the attitude (position) of the auger housing 25 to a preset origin, and is composed of, for example, a push button switch, and includes an indicator lamp 57. Is provided.

The auger housing posture operation lever 55 is an operation member for changing the posture of the auger housing 25. In other words, the auger housing posture operation lever 55 is an operation member for operating the elevating drive mechanism 16 and the rolling drive mechanism 38 to elevate and roll the auger housing 25 in accordance with the snow surface when the auger 27 performs snow removal work. . When the auger housing posture operation lever 55 is swung to the front side Frs, the rear side Rrs, the left side Les, and the right side Ris, the corresponding switches can be turned on.
The shooter operating lever 56 is an operating member for changing the direction of the shooter 29 (see FIG. 1).

FIG. 5 is an operation explanatory view of the directional speed lever employed in the present invention.
As shown in FIG. 5, the directional speed lever 53 (also referred to as “forward / reverse speed adjustment lever 53”) can be reciprocated back and forth as indicated by arrows Ad and Ba by the operator's hand, and from the “neutral range”. The snowplow 10 (see FIG. 1) can be moved forward by tilting it toward the “forward” side, and in the “forward” region, speed control can be performed so that Lf is forward at low speed and Hf is forward at high speed. Similarly, if the snowplow 10 can be moved backward from the “neutral range” to the “reverse” side, the speed control can also be performed so that Lr is low-speed reverse and Hr is high-speed reverse in the “reverse” region. Yes.

  In this example, as indicated at the left end of the figure, the potentiometer 53a (see FIG. 2) is set so that the maximum reverse speed is 0 V (volt), the maximum forward speed is 5 V, and the neutral range is 2.3 V to 2.7 V. ) To generate a voltage according to the position. The front / rear direction and the high / low speed control can be set with one lever, so the direction speed lever 53 is named.

  Next, the control system of the snow removal machine 10 will be described with reference to FIG. The control system of the snowplow 10 is centralized in the control unit 61. The control unit 61 has a configuration in which a memory 63 is built in, and various information stored in the memory 63 is appropriately read and controlled.

First, the operation of the system of the snow removal working unit 13 will be described.
The intake system of the engine 14 has a configuration in which the throttle valve 71 is controlled to open and close by the control motor 72 and the choke valve 73 is controlled to open and close by the control motor 74.
That is, the control motor 72 of the electronic governor 65 automatically adjusts the opening degree of the throttle valve 71 based on the signal from the control unit 61, and the control motor 74 of the electronic governor 65 adjusts the opening degree of the choke valve 73. It is a configuration that automatically adjusts.

The electronic governor 65 has a function of an automatic choke (also referred to as an auto choke) that automatically opens and closes the choke valve 73 according to the temperature state of the engine 14. By automatically opening and closing the choke valve 73 according to the temperature state of the engine 14 when the engine 14 is started, the engine 14 can be warmed up more appropriately and simply.
The automatic choke indicator lamp 78 can notify that the automatic choke is operating. The auto choke indicator lamp 78 may be disposed in the operation box 41.

The opening of the throttle valve 71 is detected by a throttle position sensor 75, the opening of the choke valve 73 is detected by a choke position sensor 76, and these detection signals are sent to the control unit 61.
The rotation speed (rotation speed) of the engine 14 is detected by the engine rotation sensor 77 and a detection signal is issued to the control unit 61.

  The generator 81 is rotated by a part of the output of the engine 14 and the obtained electric power is supplied to the battery 62 and also supplied to the left and right electric motors 21L and 21R and other electrical components. The remaining output of the engine 14 is used for the rotation of the auger 27 and the blower 28.

  By grasping the travel preparation lever 42 and operating the auger switch 45, the electromagnetic clutch 31 can be connected (turned on), and the auger 27 and the blower 28 can be rotated by the power of the engine 14. The electromagnetic clutch 31 can be turned off by turning the traveling preparation lever 42 free or operating the auger switch 45.

Next, the operation of the traveling units 11L and 11R will be described.
The snow remover 10 of the present invention includes left and right electromagnetic brakes 82L and 82R as brakes corresponding to parking brakes for ordinary vehicles. Specifically, the left and right electric motors 21L and 21R are braked by the left and right electromagnetic brakes 82L and 82R. These electromagnetic brakes 82L and 82R are in a brake state (on state) under the control of the control unit 61 during parking. Therefore, the electromagnetic brakes 82L and 82R are released by the following procedure.

  When the two conditions of the main switch 44 being in the ON position and the travel preparation lever 42 being gripped are satisfied and the directional speed lever 53 is switched to forward or reverse, the electromagnetic brakes 82L and 82R are in the OFF state. become.

  The control unit 61 that has obtained the position information of the directional speed lever 53 from the potentiometer 53a rotates the left and right electric motors 21L and 21R via the left and right motor drivers 84L and 84R, and rotates the rotation speed (the number of rotations) of the electric motors 21L and 21R. ) Is detected by the motor rotation sensors 83L and 83R, and feedback control is executed based on the detection signals so that the rotation speed becomes a predetermined value. As a result, the left and right drive wheels 21L, 21R rotate in a desired direction at a predetermined speed and enter a traveling state.

  Braking while driving is performed according to the following procedure. Motor drivers 84L and 84R include regenerative brake circuits 85L and 85R and short-circuit brake circuits 86L and 86R. The short circuit brake circuits 86L and 86R are brake means.

While holding the left turning lever 43L and turning on the left turning switch 43La, the control unit 61 activates the left regenerative brake circuit 85L based on the switch-on switch signal, and the left electric motor Decrease the speed of 21L.
While gripping the right turning operation lever 43R and turning on the right turning switch 43Ra, the control unit 61 operates the right regenerative brake circuit 85R based on the switch-on switch signal, and the right electric motor Decrease the speed of 21R.
That is, the snowplow 10 can be turned left only while the left turning lever 43L is being gripped. Further, the snowplow 10 can be turned to the right only while holding the right turning operation lever 43R.

  The travel can be stopped by either (1) releasing the travel preparation lever 42, (2) returning the main switch 44 to the OFF position, or (3) returning the direction speed lever 53 to the neutral position. it can.

  By swinging the auger housing posture operation lever 55 back and forth, the electric motor 16a rotates forward and backward, and the piston of the elevating drive mechanism 16 expands and contracts. As a result, the auger housing 25 and the blower case 26 move up and down. The elevation position of the auger housing 25 is detected by a height position sensor 87 (vertical movement detection unit 87), and a detection signal is issued to the control unit 61.

  By swinging the auger housing posture operation lever 55 left and right, the electric motor 38a rotates in the forward direction, and the piston of the rolling drive mechanism 38 is expanded and contracted. As a result, the auger housing 25 and the blower case 26 roll left and right. The rolling position of the auger housing 25 is detected by a rolling position sensor 88 (left / right tilt detection unit 88), and the detection signal is sent to the control unit 61.

  Next, a control flow when the control unit 61 shown in FIG. 2 is a microcomputer will be described with reference to FIGS. This control flow starts when the main switch 44 is turned on, for example, and ends when the main switch 44 is turned off. In the figure, STxx indicates a step number. Step numbers that are not specifically described proceed in numerical order. Hereinafter, a description will be given with reference to FIGS.

FIG. 6 is a control flowchart (No. 1) of the control unit according to the present invention.
ST01: The engine 14 is started by starting the main switch 44.
ST02: The operation direction of the direction speed lever 53 and the operation amount Rop are read. This signal is determined by the position of the directional speed lever 53. That is, the target speed commands of the electric motors 21L and 21R issued from the potentiometer 53a of the directional speed lever 53 to the control unit 61 are read.
ST03: It is checked whether or not the operation position of the direction speed lever 53 is the “advance position”. If YES, the process proceeds to ST04, and if NO, the control flow is terminated.

ST04: The switch signal of the auger switch 45 is read.
ST05: Check whether or not the auger switch 45 is on. If NO, the process proceeds to ST06, and if YES, the process proceeds to ST07.
ST06: The electromagnetic clutch 31 is turned off (the snow removal working unit 13 is stopped). Thereafter, the control by this control flow is finished.
ST07: The electromagnetic clutch 31 is turned on (the snow removal working unit 13 is operated). Thereafter, the process proceeds to ST08 in FIG.

FIG. 7 is a control flowchart (part 2) of the control unit according to the present invention.
ST08: The opening degree Cr of the choke valve 73 is measured. The opening degree Cr may be measured by the choke position sensor 76.
ST09: Check whether or not auto choking is in progress. If YES, the process proceeds to ST10, and if NO, the process proceeds to ST18. When the opening degree Cr of the choke valve 73 is less than 100% (fully closed or half-open state), it is determined as YES because the warm-up operation of automatically opening and closing the choke valve 73 depending on the temperature state of the engine 14 is in progress. When the opening degree Cr is 100% (fully open state), the warm-up operation is completed, and therefore it is determined as NO.

ST10: The auto choke indicator lamp 78 is turned on to notify that auto choke is being performed.
ST11: The opening degree Str of the throttle valve 71 is measured. The opening degree Str may be measured by the throttle position sensor 75.
ST12: A starting correction map (see FIG. 8) is selected from a plurality of correction maps having different characteristics. Details of the start time correction map will be described later.

ST13: Based on the starting correction map, the deceleration correction coefficient Rd of the electric motors 21L and 21R with respect to the opening degree Str of the throttle valve 71 at that time is obtained.
ST14: The target speed Ts (target rotational speed Ts) of the electric motors 21L and 21R is obtained from the operation amount Rop of the directional speed lever 53.
ST15: The target speed Ts is corrected by the deceleration correction coefficient Rd. That is, the original target speed Ts obtained from the operation amount Rop of the directional speed lever 53 is corrected by multiplying by the deceleration correction coefficient Rd, and this corrected value is set as a new target speed Ts (Ts = Ts × Rd). .

ST16: The actual speed Tr of the electric motors 21L and 21R (actual rotational speed Tr; hereinafter referred to as “actual speed Tr”) is measured. The actual speed Tr may be measured by the motor rotation sensors 83L and 83R, for example.
ST17: After executing forward control (forward rotation control) of the electric motors 21L and 21R by PID control so that the actual speed Tr of the electric motors 21L and 21R becomes the corrected target speed Ts, the process goes to ST02 in FIG. Return. The traveling units 11L and 11R travel forward.

ST18: The auto choke indicator lamp 78 is turned off to notify the completion of auto choke.
ST19: The opening degree Str of the throttle valve 71 is measured.
ST20: A normal correction map (see FIG. 9) is selected from a plurality of correction maps having different characteristics. Details of the normal correction map will be described later.

ST21: Based on the normal time correction map, a deceleration correction coefficient Rd of the electric motors 21L and 21R with respect to the opening degree Str of the throttle valve 71 at that time is obtained.
ST22: The target speed Ts of the electric motors 21L and 21R is obtained from the operation amount Rop of the directional speed lever 53.
ST23: The target speed Ts is corrected by the deceleration correction coefficient Rd (Ts = Ts × Rd).

ST24: The actual speed Tr of the electric motors 21L and 21R is measured.
ST25: After executing forward control of the electric motors 21L and 21R by PID control so that the actual speed Tr of the electric motors 21L and 21R becomes the corrected target speed Ts, the process returns to ST02 in FIG. The traveling units 11L and 11R travel forward.

In each step shown in FIG. 7, the set of ST11 to ST13 constitutes the first step, ST15 constitutes the second step, and ST17 constitutes the third step.
The control unit 61 performs the first step, the second step, and the third step when the start condition is satisfied (ST09).
The first step is a map used when the engine 14 is started. The deceleration correction coefficient Rd of the electric motors 21L and 21R decreases as the opening degree Str of the throttle valve 71 increases, and the deceleration correction coefficient Rd when fully open. Is a configuration in which the deceleration correction coefficient Rd of the electric motors 21L and 21R corresponding to the opening degree Str of the throttle valve 71 at that time is obtained from the start-up correction map having characteristics larger than 0.
The second step is configured to correct by multiplying the target speed Ts by the deceleration correction coefficient Rd.
The third step is configured to control the actual speed Tr of the electric motors 21L and 21R at the corrected target speed Ts.

Here, the start time correction map and the normal time correction map will be described with reference to FIGS.
FIG. 8 is an explanatory diagram of a start time correction map according to the present invention, where the left vertical axis is the throttle valve opening degree Str (%) and the right vertical axis is the electric motor deceleration correction coefficient Rd. FIG. 6 shows a start correction map for obtaining a deceleration correction coefficient Rd corresponding to the opening degree Str. The scale of the opening degree Str is 0% at the bottom and 100% at the top. The scale of the deceleration correction coefficient Rd is a value with 0.0 on the bottom and 1.0 on the top.

  The solid line rising upward in the figure is the valve opening characteristic line ST, which is a straight line indicating that the opening degree Str of the throttle valve changes in the range of 0 to 100%. The solid line descending to the right in the figure is the deceleration characteristic line R1, which is a straight line indicating that the deceleration correction coefficient Rd of the electric motor changes in the range of 1.0 to Rd1.

  When the opening Str is Str, for example, a horizontal line passing through the Str intersects the valve opening characteristic line ST at an intersection P1, and a vertical line extends vertically from the intersection P1 to reduce deceleration characteristics. It intersects the line R1 at the intersection point P2. The value of the deceleration correction coefficient Rd at this intersection P2 is Rd2. That is, the value of the deceleration correction coefficient corresponding to the throttle valve opening Str is Rd2.

Similarly, when Str = 0%, Rd = 1.0, and when Str = 100%, Rd = Rd1. That is, the deceleration correction coefficient Rd is closer to 1 as the opening degree Str of the throttle valve is smaller, and closer to 0 as the opening degree Str is larger.
As described above, in the start-up correction map, the deceleration correction coefficient Rd of the electric motor decreases as the throttle valve opening Str increases, and the deceleration correction coefficient when fully open (Str = 100%) is greater than zero. The map has a characteristic of Rd1 and is used when the engine 14 is started.

  FIG. 9 is an explanatory diagram of a normal time correction map according to the present invention, in which the vertical axis on the left is the throttle valve opening degree Str (%) and the right vertical axis is the deceleration correction coefficient Rd of the electric motor. The normal time correction map which obtains the deceleration correction coefficient Rd corresponding to the opening degree Str of is shown. The scale of the opening degree Str is 0% at the bottom and 100% at the top. The scale of the deceleration correction coefficient Rd is a value with 0.0 on the bottom and 1.0 on the top.

  The solid line rising upward in the figure is the valve opening characteristic line ST, which is a straight line indicating that the opening degree Str of the throttle valve changes in the range of 0 to 100%. The solid line descending to the right in the figure is the deceleration characteristic line R2, which is a straight line indicating that the deceleration correction coefficient Rd of the electric motor changes in the range of 1.0 to Rd3.

  When the opening Str is Str, for example, a horizontal line passing through the Str intersects the valve opening characteristic line ST at an intersection P1, and a vertical line extends vertically from the intersection P1 to reduce deceleration characteristics. Intersects line R2 at intersection P3. The value of the deceleration correction coefficient Rd at this intersection P3 is Rd4. That is, the value of the deceleration correction coefficient corresponding to the throttle valve opening degree Str is Rd4.

Similarly, when Str = 0%, Rd = 1.0, and when Str = 100%, Rd = Rd3. That is, the deceleration correction coefficient Rd is closer to 1 as the opening degree Str of the throttle valve is smaller, and closer to 0 as the opening degree Str is larger.
Thus, in the normal time correction map, the deceleration correction coefficient Rd of the electric motor decreases as the throttle valve opening Str increases, and the deceleration correction coefficient when fully open (Str = 100%) is greater than zero. The map has a characteristic of Rd3 and is used after the start of the engine 14 is completed.

Here, FIG. 8 is compared with FIG. In FIG. 8, the downward sloping line represented by a broken line is obtained by transcribing the deceleration characteristic line R2 shown in FIG.
As is apparent from FIG. 8, the slope of the deceleration characteristic line R1 of the starting correction map indicated by the solid line is gentler than the slope of the deceleration characteristic line R2 of the normal time correction map indicated by the broken line. The deceleration characteristic line R2 in the normal correction map has a characteristic that Rd = Rd3 when Str = 100%. Rd3 is the minimum value of the deceleration characteristic line R2, and is a small value very close to 0. On the other hand, the deceleration characteristic line R1 of the starting correction map has a characteristic that Rd = Rd1 when Str = 100%. Rd1 is the minimum value of the deceleration characteristic line R1, and is relatively larger than Rd3 (Rd1> Rd3).

  That is, the value of the deceleration correction coefficient Rd when the throttle valve 71 is fully opened is Rd3 in the deceleration characteristic line R2 of the normal time correction map, and is Rd1 larger than Rd3 in the deceleration characteristic line R1 of the start time correction map. It is characterized by that. Since “Rd1> Rd3” is set as described above, the rate at which the deceleration correction coefficient Rd decreases with the increase in the opening degree Str of the throttle valve 71 can be reduced accordingly. The deceleration correction coefficients Rd1 and Rd3 when the throttle valve 71 is fully open may be set to an optimum value in consideration of the characteristics of the snowplow 10 and the engine 14.

  For example, when considering Str = Str, according to the deceleration characteristic line R2 of the normal correction map, Rd = Rd4, which is small. On the other hand, according to the deceleration characteristic line R1 of the starting correction map, Rd = Rd2, which is larger than Rd4 (Rd2> Rd4).

Next, the performance of the snowplow 10 having the above configuration will be described with reference to FIGS. 2 and 8 to 10.
FIG. 10 is a diagram for explaining the performance of the snowplow according to the present invention. The horizontal axis represents elapsed time, the left vertical axis represents the throttle valve opening Str (%), and the right vertical axis represents the choke valve opening. The performance of the snowplow is shown as Cr (%) and the actual speed Tr (m / sec) of the electric motor.

When t1 is the time when the engine 14 is started and t2 is the time when the warm-up operation is completed, the opening degree Cr of the choke valve 73 is 0% at t1 and 100% at t2. . That is, the opening degree Cr of the choke valve 73 gradually increases from 0% to 100% according to the warm-up state.
At substantially the same time as starting the engine 14, when the snow removal working unit 13 is driven by the engine 14 while the traveling units 11L and 11R are moved forward by the electric motors 21L and 21R, the load on the engine 14 is large. The opening degree Str of the valve 71 increases rapidly. That is, the opening degree Str of the throttle valve 71 becomes larger than necessary.

On the other hand, during the auto choke from the time point t1 to the time point t2, that is, during the warm-up operation, the electric correction corresponding to the opening degree Str of the throttle valve 71 at that time is performed using the start time correction map shown in FIG. The deceleration correction coefficient Rd of the motors 21L and 21R is obtained.
Since the actual speed Tr of the electric motors 21L and 21R is controlled based on the target speed Ts corrected by the deceleration correction coefficient Rd, the actual speed Tr of the electric motors 21L and 21R is maintained even when the throttle valve 71 is fully opened. There is no minimum. In addition, since the deceleration correction coefficient Rd in the fully open state is set to be larger than 0, the rate at which the deceleration correction coefficient Rd decreases with the increase in the opening Str of the throttle valve 71 can be reduced accordingly.
For this reason, even if the opening degree Str of the throttle valve 71 increases rapidly, the actual speed Tr of the electric motors 21L and 21R decreases relatively slowly.

  Furthermore, since the deceleration correction coefficient Rd at that time is obtained from the starting correction map, the deceleration correction coefficient Rd can be obtained very quickly, and based on the target speed Ts corrected by the deceleration correction coefficient Rd. Thus, the actual speed Tr of the electric motors 21L and 21R can be controlled more quickly. Therefore, when the engine is started, the responsiveness (response) of the speed change of the electric motors 21L and 21R to the load applied to the engine 14 is good. For this reason, the snow removal workability of the snow removal machine 10 can be further enhanced.

  After the time t2 when the auto choke, that is, the warm-up operation is completed, the engine 14 is in a normal operating state, so that the normal time correction map shown in FIG. 9 is used to correspond to the opening degree Str of the throttle valve 71 at that time. The deceleration correction coefficient Rd of the electric motors 21L and 21R to be obtained is obtained. Based on the target speed Ts corrected by the deceleration correction coefficient Rd, the actual speed Tr of the electric motors 21L and 21R is controlled.

Next, a modified example of the snow removal machine 10 will be described with reference to FIGS. 11 and 12.
The modified snowplow 10 has the configuration of ST11 to ST15 in FIG. 7 (the configuration surrounded by an imaginary line frame) and the configuration of ST101 to ST107 shown in FIG. 11 (the configuration surrounded by an imaginary line frame). The other configuration is the same as the configuration shown in FIGS. 1 to 10 and the description thereof is omitted.

FIG. 11 is a control flowchart of a modification of the control unit according to the present invention.
ST08: The opening degree Cr of the choke valve 73 is measured.
ST09: Check whether or not the auto choke is being performed. If YES, the process proceeds to ST10, and if NO, the process proceeds to ST18 (see FIG. 7).
ST10: The auto choke indicator lamp 78 is turned on.

ST101: The opening degree Str of the throttle valve 71 is measured.
ST102: A normal correction map (see FIG. 9) is selected from a plurality of correction maps having different characteristics.
ST103: Based on the normal time correction map, the deceleration correction coefficient Rd of the electric motors 21L and 21R with respect to the opening degree Str of the throttle valve 71 at that time is obtained.
ST104: An initial correction map (see FIG. 12) is selected from a plurality of correction maps having different characteristics. Details of the initial correction map will be described later.

ST105: Based on the initial correction map, initial correction coefficients Rch of the electric motors 21L and 21R with respect to the opening degree Cr of the choke valve 73 at that time are obtained.
ST106: The target speed Ts of the electric motors 21L and 21R is obtained from the operation amount Rop of the directional speed lever 53.
ST107: The target speed Ts is corrected with the deceleration correction coefficient Rd and the initial correction coefficient Rch. That is, the original target speed Ts obtained from the operation amount Rop of the directional speed lever 53 is multiplied by the deceleration correction coefficient Rd and further multiplied by the reciprocal of the initial correction coefficient Rch, and the corrected value is set as a new target value. The speed is Ts (Ts = Ts × Rd × 1 / Rch).

ST16: The actual speed Tr of the electric motors 21L and 21R is measured.
ST17: After executing forward control (forward rotation control) of the electric motors 21L and 21R by PID control so that the actual speed Tr of the electric motors 21L and 21R becomes the corrected target speed Ts, the process goes to ST02 in FIG. Return. The traveling units 11L and 11R travel forward.

In each step of the modification shown in FIG. 11, the set of ST08, ST104, and ST105 constitutes the first step. The set of ST101 to ST103 constitutes the second step. ST107 constitutes the third step, and ST17 constitutes the fourth step.
The control unit 61 of the modified example executes the first step, the second step, the third step, and the fourth step when the start condition is satisfied (ST09).

  The first step is a map used at the time of starting the engine 14, and an initial correction map having a characteristic that the initial correction coefficient Rch of the electric motors 21L and 21R increases as the opening degree Cr of the choke valve 73 increases (see FIG. 12), the initial correction coefficient Rch of the electric motors 21L and 21R corresponding to the opening degree Cr of the choke valve 73 at that time is obtained.

  The second step is a map used after the start of the engine 14 is completed, and is a normal time correction map having a characteristic that the deceleration correction coefficient Rd of the electric motors 21L and 21R decreases as the opening degree Str of the throttle valve 71 increases. (See FIG. 9), the deceleration correction coefficient Rd of the electric motors 21L and 21R corresponding to the opening degree Str of the throttle valve 71 at that time is obtained.

The third step is configured to perform correction by multiplying the target speed Ts by the reciprocal of the initial correction coefficient Rch and the deceleration correction coefficient Rd.
The fourth step is configured to control the actual speed Tr of the electric motors 21L and 21R at the corrected target speed Ts.

Here, the initial correction map will be described with reference to FIG.
FIG. 12 is an explanatory diagram of an initial correction map according to the present invention. The vertical axis on the left side of the drawing is the choke valve opening Cr (%), and the right vertical axis is the initial correction coefficient Rch of the electric motor. An initial correction map for obtaining an initial correction coefficient Rch corresponding to the opening degree Cr is shown. The scale of the opening degree Cr is 0% at the bottom and 100% at the top. The scale of the initial correction coefficient Rch is a value with 0.0 on the bottom and 1.0 on the top.

  The solid line rising upward in the figure is a choke valve opening characteristic line Ch, which is a straight line showing that the opening degree Cr of the choke valve changes in the range of 0 to 100%. A broken line rising upward in the figure is an initial correction characteristic line Rc, which is a straight line indicating that the initial correction coefficient Rch of the electric motor changes in the range of Rch1 to 1.0. Rch1, which is the minimum value of the initial correction coefficient Rch, is a value slightly larger than 0 (0 <Rch1 <1). The maximum value of the initial correction coefficient Rch is 1.0.

  To explain how to view this figure, for example, when the opening degree Cr is Cre, a horizontal line passing through Cre intersects the choke valve opening characteristic line Ch at an intersection point Q1, and a vertical line extends vertically from this intersection point Q1 to the initial value. Crosses the correction characteristic line Rc at the intersection Q2. The value of the initial correction coefficient Rch at the intersection Q2 is Rch2. That is, the value of the initial correction coefficient Rch corresponding to the opening degree Cre of the choke valve is Rch2.

Similarly, when Cr = 0%, Rch = Rch1, and when Cr = 100%, Rch = 1.0. That is, the initial correction coefficient Rch is closer to 0 as the opening degree Cr of the choke valve is smaller, and closer to 1 as the opening degree Cr is larger.
Thus, the initial correction map shows that the initial correction coefficient Rch of the electric motor increases with an increase in the opening degree Cr of the choke valve, and the initial correction coefficient Rch in the fully closed state (Cr = 0%) is greater than zero. The map has a characteristic of a large Rch1 and is used when the engine 14 is started.

  As is clear from the above description, in the modified example, the initial correction map having the characteristic that the initial correction coefficient Rch of the electric motors 21L and 21R increases with the increase in the opening degree Cr of the choke valve 73 (see FIG. 12). In addition, a normal time correction map (see FIG. 9) having a characteristic that the deceleration correction coefficient Rd of the electric motors 21L and 21R decreases in accordance with the increase in the opening degree Str of the throttle valve 71 is prepared.

  When the engine 14 is started, the initial correction coefficient Rch of the electric motors 21L and 21R corresponding to the opening degree Cr of the choke valve 73 is obtained from the initial correction map, and the occasional throttle valve 71 is obtained from the normal correction map. The deceleration correction coefficient Rd of the electric motors 21L and 21R corresponding to the opening degree Str is obtained, and the target speed Ts is obtained by multiplying the target speed Ts of the electric motors 21L and 21R by the reciprocal of the initial correction coefficient Rch and the deceleration correction coefficient Rd. It can be corrected very quickly. Based on the corrected target speed Ts, the speeds of the electric motors 21L and 21R can be controlled more quickly. That is, the same operation and effect as the embodiment shown in FIGS.

  More specifically, as shown in FIG. 10, when the engine 14 is started, the opening degree Cr of the choke valve 73 gradually increases according to the warm-up state. On the other hand, when the snow removal working unit 13 is driven by the engine 14 while the traveling units 11L and 11R are advanced by the electric motors 21L and 21R almost simultaneously with the start of the engine 14, the load on the engine 14 is large. The opening degree Str of the throttle valve 71 increases abruptly.

  That is, when the snow removal work is performed almost simultaneously with the start of the engine 14, (1) when the engine 14 is hardly warmed up, the opening degree Cr of the choke valve 73 is small and the opening degree Str of the throttle valve 71 is large. . (2) As the warm-up progresses, the opening degree Cr of the choke valve 73 increases and the opening degree Str of the throttle valve 71 decreases.

  In the modification, paying attention to this point, the correction is made not only by multiplying the target speed Ts of the electric motors 21L and 21R by the deceleration correction coefficient Rd but also by the reciprocal of the initial correction coefficient Rch. By doing in this way, the actual speed Tr of the electric motors 21L and 21R can be controlled more precisely and more quickly. Therefore, when the engine is started, the responsiveness (response) of the speed change of the electric motors 21L and 21R to the load applied to the engine 14 is good. For this reason, the snow removal workability of the snow removal machine 10 can be further enhanced.

The description of the above embodiments and modifications is summarized as follows.
That is, the snowplow 10 of the present invention is an electronic device that adjusts the respective opening degrees Cr and Str of the engine 14 that drives the snow removal work unit 13 such as an auger provided in the machine body 19 and the choke valve 73 and the throttle valve 71 of the engine 14. The electric governor 65 and the electric motors 21L, 21R that change the traveling speed of the traveling units 11L, 11R that travel the airframe 19 and the electronic governor 65 are controlled, and the electric motors 21L, 21R are associated with the electronic governor 65. A control unit 61 that controls the traveling speed, and a target speed adjustment unit 53 (directional speed lever 53) that instructs the control unit 61 to specify the target speed Ts of the electric motors 21L and 21R are provided.

  When the starting condition that the choke valve 73 is being driven is satisfied (ST09 in FIG. 7 or ST09 in FIG. 11), the controller 61 decreases the travel speed with respect to the increase in the opening degree Str of the throttle valve 71. The ratio (the set of ST11 to ST17 in FIG. 7 or the set of ST101 to ST107, ST16 and ST17 in FIG. 11) is smaller than when the choke valve 73 is stopped (the set of ST19 to ST25 in FIG. 7). It is the structure which controls to.

  As described above, according to the present invention, in the engine start state in which the choke valve 73 is driven, control is performed such that the rate at which the traveling speed decreases with respect to the increase in the opening degree Str of the throttle valve 71 is smaller than after the start is completed. Decided to do.

  At substantially the same time as starting the engine 14, when the snow removal working unit 13 is driven by the engine 14 while the traveling units 11L and 11R are moved forward by the electric motors 21L and 21R, the load on the engine 14 is large. The opening degree Str of the valve 71 increases rapidly.

  On the other hand, in the present invention, even if the opening degree Str of the throttle valve 71 increases rapidly, the actual speed Tr of the electric motors 21L and 21R is decreased relatively slowly. For this reason, the speed of the running speed of the snowplow 10 also decreases relatively slowly. As a result, the snow removal work by the snow removal working unit 13 can be promoted. Thus, since the snow removal workability during the warm-up operation of the engine 14 is improved, the snow removal workability of the snow removal machine 10 can be further improved.

  Further, the control unit 61 has two conditions: a condition that the traveling units 11L and 11R are being operated forward (ST03 in FIG. 6), and a condition that the snow removal work unit 13 is performing a snow removal operation (ST05 in FIG. 6). Only when the condition is satisfied, the rate at which the traveling speed decreases with respect to the increase in the opening degree Str of the throttle valve 71 is controlled to be smaller than when the choke valve 73 is stopped.

  As described above, in the present invention, the throttle valve is operated only when the snow removal machine 13 is removing snow while the snow remover 10 is traveling forward in the engine starting state where the choke valve 73 is driven, that is, only when removing snow. The rate at which the traveling speed decreases with respect to the increase in the opening degree Str of 71 is made smaller.

  When the snow removal work is not being performed, the snow removal machine 10 is merely moved, so that the load due to snow removal is not applied to the engine 14. In the present invention, the traveling speed can be freely set regardless of the state of the engine 14, so that the mobility of the snowplow 10 is enhanced.

  In the present embodiment, the snow removal machine 10 is not limited to the auger type snow removal machine as long as the load applied to the snow removal working unit 13 increases according to the traveling speed.

  In the control flow, the drive control method for the left and right electric motors 21L and 21R may be, for example, a pulse width modulation method (PWM method) for supplying a pulse voltage to the motor terminals. In response to the control signal of the control unit 61, the motor drivers 84L and 84R can control the rotation of the electric motors 21L and 21R by issuing a pulse signal whose pulse width is controlled.

  The snow remover 10 according to the present invention drives the snow removal working unit 13 with the engine 14 and drives the traveling speeds of the traveling units 11L and 11R with the electric motors 21L and 21R so that the engine 14 and the electric motors 21L and 21R are related. The self-propelled working machine increases the load applied to the working unit 13 in accordance with the traveling speed. Such a self-propelled working machine is suitable for an auger-type snow removal machine that scrapes and removes snow with a front auger 27 while traveling forward.

It is a side view of the snow removal machine (work machine) which concerns on this invention. It is a typical top view and control system diagram of the snowplow according to the present invention. It is a perspective view of the operation part which concerns on this invention. It is a top view of the operation part which concerns on this invention. It is action | operation explanatory drawing of the direction speed lever employ | adopted by this invention. It is a control flowchart (the 1) of the control part concerning the present invention. It is a control flowchart (the 2) of the control part which concerns on this invention. It is explanatory drawing of the starting correction map which concerns on this invention. It is explanatory drawing of the normal time correction map which concerns on this invention. It is performance explanatory drawing of the snow remover which concerns on this invention. It is a control flowchart of the modification of the control part which concerns on this invention. It is explanatory drawing of the initial correction map which concerns on this invention. It is a block diagram of the conventional auger type snow remover. It is performance explanatory drawing of the conventional snow remover.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Snow removal machine, 11L, 11R ... Traveling part, 13 ... Snow removal working part, 14 ... Engine, 19 ... Airframe, 21L, 21R ... Electric motor, 45 ... Auger switch, 53 ... Target speed adjustment part (directional speed lever), 61 ... Control unit, 65 ... Electronic governor, 71 ... Throttle valve, 73 ... Choke valve, Cr ... Choke valve opening, Rch ... Electric motor initial correction coefficient, Rd ... Electric motor deceleration correction coefficient, Str ... Throttle Valve opening, Tr: actual speed of the electric motor, Ts: target speed of the electric motor.

Claims (4)

An engine that drives a snow removal working unit such as an auger provided in the fuselage, an electronic governor that adjusts each opening degree of the choke valve and the throttle valve of the engine, an electric motor that drives a travel unit that runs the fuselage, A control unit for controlling the electronic governor and controlling the traveling speed by associating the electric motor with the electronic governor, and a target speed adjusting unit for instructing the target speed of the electric motor to the control unit. A snowblower,
When the control unit satisfies a start condition that the choke valve is being driven, a ratio of the travel speed decreasing with respect to an increase in the opening degree of the throttle valve is set from the time when the choke valve is stopped. A snow remover characterized in that it is controlled so as to be smaller. The control unit is to execute when the start condition is satisfied,
A map used when starting the engine, wherein the deceleration correction coefficient of the electric motor decreases as the throttle valve opening increases, and the deceleration correction coefficient when fully open is greater than zero. Obtaining a deceleration correction coefficient of the electric motor corresponding to the opening of the throttle valve at that time from a time correction map;
Correcting by multiplying the deceleration correction coefficient by the target speed;
Controlling the speed of the electric motor at the corrected target speed;
The snow remover according to claim 1, further comprising: The control unit is to execute when the start condition is satisfied,
From the initial correction map having a characteristic that the initial correction coefficient of the electric motor increases with an increase in the opening of the choke valve, the map used at the time of starting the engine, the opening of the choke valve at that time Obtaining an initial correction coefficient of the electric motor corresponding to
A map used after the completion of the engine start, from a normal correction map having a characteristic that the deceleration correction coefficient of the electric motor decreases as the opening of the throttle valve increases. Obtaining a deceleration correction coefficient of the electric motor corresponding to the opening;
Correcting by multiplying the target speed by the reciprocal of the initial correction coefficient and the deceleration correction coefficient;
Controlling the speed of the electric motor at the corrected target speed;
The snow remover according to claim 1, further comprising: The control unit controls the opening degree of the throttle valve only when the two conditions of the condition that the traveling unit is operating forward and the condition that the snow removal working unit is performing snow removal are satisfied. The snowplow according to claim 1, 2 or 3, wherein a rate at which the traveling speed decreases with respect to an increase is controlled to be smaller than when the choke valve is stopped. .

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