JP2008285973A - Self-propelled snow plow - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress power consumption of a traveling electric motor in a self-propelled snow plow. <P>SOLUTION: The self-propelled snow plow 100 comprises a snow removing device 102, traveling devices 104L and 104R, and traveling electric motors 10L and 10R for driving only the traveling devices. The traveling devices are driven only by the traveling electric motors. Each of the traveling electric motors comprises a motor shaft, a rotor provided on the motor shaft, and a stator disposed in conformation to the rotor. One of the rotor and the stator is divided to a plurality of members in the direction of the motor shaft, and each of the plurality of divided members includes an electrically independent coil. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a snow removal work device and a self-propelled snow remover including a traveling device capable of self-propelling by an electric motor.

Some self-propelled snowplows, such as an auger-type snowplow, increase the load on the working 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. Development of such a self-propelled snow removal machine is underway (see, for example, Patent Document 1).
JP 2004-225308 A

  A conventional self-propelled snowplow shown in Patent Document 1 includes an auger, an engine that drives the auger, a pair of left and right crawlers, and a pair of left and right traveling electric motors that independently drive the pair of crawlers. It is something that. The auger is driven only by the engine. The pair of crawlers is driven only by the pair of traveling electric motors. The pair of traveling electric motors drives only the pair of crawlers.

  When the crawler travels while removing snow with the auger, that is, when the self-propelled snow remover travels with snow, the load on the crawler is large. Moreover, since the amount of snow removed by the auger increases as the traveling speed increases, the load on the crawler also increases rapidly. For this reason, when performing snow removal work, the self-propelled snow removal machine is driven at a low speed. The characteristics of the electric motor for traveling when performing snow removal work are required to be low-speed rotation and large torque.

  By the way, in a self-propelled snow remover, there is a case where it is desired to run temporarily without performing snow removal work by an auger (moving running). For example, when a self-propelled snowplow is taken in and out of a storage location or moved from a storage location to a nearby snow removal location. In this case, it is preferable in terms of work efficiency that the self-propelled snowplow is run at high speed. Moreover, since no snow removal work is performed, the load on the crawler is small. The characteristics of the electric motor for traveling when moving and traveling may be high-speed rotation and low torque.

  In this way, the characteristics required for the electric motor for traveling are completely different between when the self-propelled snowplow is driven to remove snow and when it is simply moved. Conventional self-propelled snowplows are equipped with a traveling electric motor that satisfies both completely different characteristics. That is, the traveling electric motor can generate a large torque. Therefore, even when only the self-propelled snowplow is moved, the power consumption must be relatively large.

On the other hand, a battery that supplies electric power to the traveling electric motor often has a relatively small capacity. This is because, by operating the engine, electric power can be constantly supplied from the engine to the traveling electric motor via the generator, so that a large-capacity battery is not necessary.
However, it is troublesome to operate the engine just to move the self-propelled snowplow. When only the self-propelled snowplow is moved, it is more preferable that electric power is supplied from only a small-capacity battery and the electric motor for traveling can be operated.

  This invention makes it a subject to provide the technique which can suppress the power consumption of the electric motor for driving | running | working in a self-propelled snow remover.

In the invention according to claim 1, in a self-propelled snowplow including a snow removal work device such as an auger or a dozer, a travel device such as a crawler or a wheel, and a travel electric motor for driving only the travel device. ,
The traveling device is configured to be driven only by the traveling electric motor,
The electric motor for traveling includes a motor shaft, a rotor provided on the motor shaft, and a stator disposed so as to correspond to the rotor.
One of the rotor and the stator is divided into a plurality of members in the motor axial direction,
The plurality of divided members have electrically independent windings for each of the divided members.

  According to a second aspect of the present invention, in the first aspect of the present invention, a plurality of driver circuits that individually supply a driving current to each of the divided windings of each member, and a control signal is issued to the plurality of driver circuits. And a control unit that controls the electric motor for traveling.

  According to a third aspect of the present invention, in the second aspect, when the control unit determines that a condition that a drive current supplied to the traveling electric motor is lower than a predetermined reference current is satisfied. The plurality of driver circuits are controlled so that a driving current is supplied only to a predetermined winding of the divided windings of each member.

  According to a fourth aspect of the present invention, in the second aspect of the present invention, the control unit includes two conditions: a condition that the snow removal work by the snow removal work device is stopped and a condition that the traveling device is operated to travel. When it is determined that the condition is satisfied, the plurality of driver circuits are controlled so that a driving current is supplied only to a predetermined winding of the divided windings of each member. To do.

In the invention according to claim 1, in the rotor and the stator, the member having a plurality of windings is divided into a plurality in the motor axial direction including the plurality of windings, The plurality of windings divided in the motor axis direction are electrically independent from each other.
For this reason, for example, the torque generated by the traveling electric motor can be reduced by supplying the drive current to only one of the plurality of windings divided in the motor axial direction.
On the other hand, the torque generated by the traveling electric motor can be increased by supplying the drive current to all the windings.
In this way, since only the supply of the drive current to the plurality of windings is changed, the power consumption can be suppressed despite the simple configuration and the small electric motor for traveling.

In the invention according to claim 2, the driver circuit is divided into a plurality of parts so as to individually supply a driving current for each of the divided windings of each member. A plurality of driver circuits can be individually controlled by the control unit.
For this reason, the current supply capability of each driver circuit can be small. Each driver circuit can be reduced in size.
The driver circuit generates heat. On the other hand, since the driver circuit is divided into a plurality of parts, the heat radiation from each driver circuit can be dispersed. For this reason, the heat sink for cooling each driver circuit can be reduced in size. Therefore, the power unit including the electric motor, the driver circuit, and the control unit can be reduced in size.

According to the third aspect of the present invention, when the self-propelled snowplow is run without performing the snow removal work by the snow removal work device, the load applied to the electric motor is small. As a result, the drive current supplied to the traveling electric motor is less than a predetermined reference current. At this time, the control unit performs control so that the drive current is supplied only to a predetermined winding among the plurality of windings. As a result, the torque generated by the traveling electric motor is small.
On the other hand, when the self-propelled snowplow is run while performing snow removal work by the snow removal work device, the load applied to the running electric motor is large. As a result, the drive current supplied to the traveling electric motor reaches a predetermined reference current. At this time, the control unit may perform control so as to supply drive current to all the windings, for example. As a result, the torque generated by the traveling electric motor is large. In addition, the traveling electric motor can be rotated at a low speed in accordance with the speed operation of the operator.
In this way, since the supply of the drive current to the traveling electric motor is only changed depending on the presence or absence of the snow removal work by the snow removal work device, the power consumption of the traveling electric motor can be suppressed with a simple configuration.

According to the fourth aspect of the present invention, when the self-propelled snowplow is run without performing the snow removal work by the snow removal work device, the load applied to the electric motor is small. At this time, the control unit performs control so that the drive current is supplied only to a predetermined winding among the plurality of windings. As a result, the torque generated by the traveling electric motor is small.
On the other hand, when the self-propelled snowplow is run while performing snow removal work by the snow removal work device, the load applied to the electric motor for running is large. At this time, the control unit may perform control so as to supply drive current to all the windings, for example. As a result, the torque generated by the traveling electric motor is large. In addition, the traveling electric motor can be rotated at a low speed in accordance with the speed operation of the operator.
In this way, the power consumption of the traveling electric motor can be suppressed with a simple configuration because only the drive current supply to the traveling electric motor is changed depending on the presence or absence of the snow removal work by the snow removal work device.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.
First, the configuration of the traveling electric motor will be described with reference to FIGS. FIG. 1 is a sectional view of a traveling electric motor according to the present invention. 2 is a cross-sectional view of the traveling electric motor shown in FIG. 1 as viewed from the motor axial direction. FIG. 3 is a cross-sectional view of the rotor block shown in FIG.

  As shown in FIGS. 1 and 2, the traveling electric motor 10 is a brushless inner rotor type DC motor including a rotor block 20 and a stator block 30. Hereinafter, the traveling electric motor 10 is simply referred to as an “electric motor 10”.

First, the rotor block 20 will be described.
As shown in FIGS. 1 and 3, the rotor block 20 includes one motor shaft 21, a plurality of rotors 22, 23, one inter-rotor spacer 24, and one fixing ring 25.
As shown in FIG. 3, one end 21a of the motor shaft 21 is configured as an output end for outputting torque, and the other end 21b of the motor shaft 21 is configured as a supported end. The motor shaft 21 has a disk-like flange 21c formed integrally in the middle of the length close to the output end 21a.

  As shown in FIG. 3, the plurality of (for example, two) rotors 22 and 23 are inner rotors divided into a plurality of members in the axial direction of the motor shaft 21. An annular inter-rotor spacer 24 is interposed between the two rotors 22 and 23. For this reason, the two rotors 22 and 23 are arranged with a constant interval S <b> 1 (air gap) in the axial direction of the motor shaft 21. The constant interval S1 is defined by the length of the inter-rotor spacer 24. As a matter of course, it is preferable that the length and the outer diameter of the inter-rotor spacer 24 are set such that the magnetic flux does not flow between the rotors 22 and 23.

  The two rotors 22 and 23 are annular members fixed to the motor shaft 21 by press-fitting, for example. Of the two rotors 22, 23, the one disposed near the output end 21a is referred to as a first rotor 22, and the one disposed near the supported end 21b is referred to as a second rotor 23. The first rotor 22 is disposed at a position in contact with the flange 21c.

FIG. 4 is a view of each part of the rotor block 20 shown in FIG. 3 as viewed from the motor shaft direction. FIG. 4A shows the first rotor 22. FIG. 4B shows the inter-rotor spacer 24. FIG. 4C shows the second rotor 23.
2 and 4, the phases of the first and second rotors 22 and 23 and the inter-rotor spacer 24 are set to 0 ° with respect to one circumference, respectively, and 90 ° and 180 ° clockwise in the figure. 270 °.

  As shown in FIGS. 3 and 4, each of the rotors 22 and 23 is configured by laminating a large number of disk-shaped laminated plates made of magnetic thin plates. A plurality of (for example, eight) permanent magnets 26 are fixed by press-fitting in the vicinity of the outer peripheral surfaces of the rotors 22 and 23 at an equal pitch in the circumferential direction. The eight permanent magnets 26 are elongated plate-like members magnetized in the direction of the plate surface. These permanent magnets 26 are arranged radially with one surface facing outward and extend along the motor shaft 21. Further, these permanent magnets 26 are alternately arranged with N and S poles in the circumferential direction.

  Further, each rotor 22, 23 has a plurality of vent holes 22 a, 23 a between the motor shaft 21 and each permanent magnet 26. These vent holes 22 a and 23 a are arranged in the same phase with respect to each permanent magnet 26 and penetrate along the motor shaft 21. By providing the plurality of vent holes 22a and 23a, the heat at the center of each rotor 22 and 23 can be dissipated to the atmosphere.

  The rotor block 20 fits the motor shaft 21 with the first rotor 22, the inter-rotor spacer 24, the second rotor 23, and the fixing ring 25 in this order from the supported end 21b toward the output end 21a. By combining, they are assembled together.

  The inter-rotor spacer 24 is loosely fitted to the motor shaft 21 (clearance fit). The fitting method of the two rotors 22 and 23 to the motor shaft 21 and the fitting method of the fixing ring 25 to the motor shaft 21 are “tight fit”. “Fitting” is a fit that always allows “interference” when the hole and shaft are assembled, that is, the maximum diameter of the hole is smaller than the minimum diameter of the shaft, or in extreme cases Is an equal mating scheme. The “interference” is the difference between the diameter of the hole with respect to the diameter of the shaft before the combination when the diameter of the shaft is larger than the diameter of the hole.

  Thus, the two rotors 22 and 23 fixed to the motor shaft 21 by press-fitting are attached to the motor shaft 21 so as not to rotate and to slide in the axial direction. Since it is only press-fitted, there is no need to apply anti-rotation processing such as keyway or serration. For this reason, an assembling operation is easy with an extremely simple configuration.

As shown in FIGS. 3 and 4, the first and second rotors 22 and 23 are arranged so that their phases are shifted from each other by an angle θ2. That is, the phase of the second rotor 23 is shifted from the reference 0 ° in the clockwise direction by the angle θ2 with respect to the first rotor 22. The angle θ2 is 7.5 ° as will be described later.
In the first rotor 22, one vent hole 22a and one permanent magnet 26 are arranged at a reference 0 ° position, and another vent hole 22a and another permanent magnet 26 are arranged in order clockwise. . In the second rotor 23, one vent hole 23a and one permanent magnet 26 are arranged at a position shifted in phase by an angle θ2 clockwise from the reference 0 °, and the other vent holes are sequentially clockwise. 23a and another permanent magnet 26 are arranged.

  More specifically, the inter-rotor spacer 24 has a first positioning hole 24a opened in the surface facing the first rotor 22 and a second positioning hole 24b opened in the surface facing the second rotor 23. The first and second positioning holes 24a and 24b are bottomed holes that are arranged out of phase by an angle θ2.

The first positioning hole 24a is disposed at a position shifted from the reference 0 ° by the angle θ1 in the clockwise direction in the inter-rotor spacer 24. The angle θ1 is 22.5 °. The second positioning hole 24b is disposed at a position further offset from the first positioning hole 24a by an angle θ2 in the clockwise direction. That is, the phase of the second positioning hole 24b is shifted by the angle θ2 in the clockwise direction with respect to the first positioning hole 24a.
The first rotor 22 has a rotor-side first positioning hole 22b that penetrates to a position facing the first positioning hole 24a (a position shifted by an angle θ1 clockwise from the reference 0 °). The 2nd rotor 23 has the rotor side 2nd positioning hole 23b penetrated in the position facing the 2nd positioning hole 24b.

  By fitting one first positioning pin 27 into each first positioning hole 22b, 24a and fitting one second positioning pin 28 into each second positioning hole 23b, 24b, the two rotors 22, 23 Are arranged out of phase with each other. Therefore, the phases of the two rotors 22 and 23 can be adjusted by a simple positioning operation with a very simple configuration. In addition, the presence or absence of alignment by the positioning pins 27 and 28 is arbitrary.

Next, the stator block 30 will be described.
FIG. 5 is a cross-sectional view of the stator block shown in FIG. 1 in an exploded state.
As shown in FIGS. 1, 2, and 5, the stator block 30 includes a plurality of stators 31, 32, one inter-stator spacer 33, and two covers 34, 35.
As shown in FIGS. 1 and 5, the plurality of (for example, two) stators 31 and 32 are divided into a plurality of members in the axial direction of the motor shaft 21 and correspond to the rotors 22 and 23 individually. It is the cyclic | annular outer stator arrange | positioned in this. Of the two stators 31 and 32, the one arranged so as to correspond to the first rotor 22 is called a first stator 31, and the one arranged so as to correspond to the second rotor 23 is called a second stator 32. .

  The rotors 22 and 23 and the stators 31 and 32 are arranged concentrically with respect to the motor shaft 21. The rotors 22 and 23 are arranged with a slight gap (air gap) inside the corresponding stators 31 and 32.

  An annular inter-stator spacer 33 is interposed between the two stators 31 and 32. For this reason, the two stators 31 and 32 are arranged with a constant interval S <b> 2 (air gap) in the axial direction of the motor shaft 21. The constant interval S2 is defined by the length of the inter-stator spacer 33. The outer diameter of the inter-stator spacer 33 is substantially the same as the outer diameter of the stators 31 and 32. As a matter of course, it is preferable that the length, the inner diameter, and the outer diameter of the inter-stator spacer 33 are set so that magnetic flux does not flow between the stators 31 and 32.

  Each of the stators 31 and 32 is configured by laminating a large number of laminated plates made of magnetic thin plates. More specifically, each of the stators 31 and 32 is formed by connecting, in the circumferential direction, a plurality of teeth 36 each made of a thin plate formed in a T shape when viewed from the motor shaft direction as shown in FIG. It is configured in an annular shape. The plurality of teeth 36 is a combination of the number corresponding to the number of poles of the stators 31 and 32, for example, 12 in the circumferential direction. The salient poles 36 a of the teeth 36 are arranged so as to extend toward the motor shaft 21. As a result, the twelve salient poles 36 a are radially arranged with respect to the motor shaft 21. Each of the twelve salient poles 36 a has a bobbin 37. An electric winding 38 is wound around each bobbin 37.

  As described above, each of the stators 31 and 32 has twelve windings 38 arranged in the circumferential direction corresponding to the eight permanent magnets 26, respectively. Hereinafter, the winding 38 is simply referred to as “winding 38”. The winding direction of all the windings 38 is the same direction. As will be described in detail later, each of the twelve windings 38 is grouped into three winding phases 61 to 63 (see FIG. 9).

  Of the two covers 34 and 35, the one disposed on the first stator 31 side is referred to as a first cover 34, and the one disposed on the second stator 32 side is referred to as a second cover 35. The first cover 34 covers the outer side of the first stator 31 in the axial direction, and supports the output end 21 a of the motor shaft 21 via a bearing 41 so as to be rotatable. The second cover 35 covers the outer side of the second stator 32 in the axial direction, and supports the supported end portion 21 b of the motor shaft 21 via a bearing 42 so as to be rotatable.

As shown in FIGS. 2 and 5, the stators 31 and 32, the inter-stator spacer 33, and the covers 34 and 35 are connected to each other by a plurality of bolts 43. 34a and 35a are provided in the vicinity of the outer periphery. The bolt hole of the first cover 34 is a screw hole.
The stator block 30 is integrally assembled by stacking the first stator 31, the inter-stator spacer 33, the second stator 32, and the second cover 35 in this order on the first cover 34 and connecting them with a plurality of bolts 43. It is done.

  2 and 5, the phases of the first and second stators 31 and 32 and the inter-stator spacer 33 are set to 0 ° on the basis of one circumference and 90 ° and 180 ° clockwise in the figure. 270 °.

  As shown in FIGS. 2 and 5, the first and second stators 31 and 32 are arranged in phase with each other. In the first and second stators 31 and 32, one winding 38 is arranged at a reference 0 ° position, and another winding 38 is arranged in order in the clockwise direction.

  More specifically, the inter-stator spacer 33 has two first positioning holes 33b and 33b (see FIG. 5) opened on the surface facing the first stator 31, and 2 opened on the surface facing the second stator 32. Two second positioning holes 33c, 33c (see FIG. 5). The first and second positioning holes 33b and 33c are bottomed holes arranged in phase with each other. The two first positioning holes 33b and 33b are arranged symmetrically with respect to the motor shaft 21 (at positions of 0 ° and 180 °). The two second positioning holes 33c and 33c are arranged symmetrically with respect to the motor shaft 21 (at positions of 0 ° and 180 °).

The first stator 31 has a stator-side first positioning hole 31b that penetrates at a position facing the first positioning hole 33b. The second stator 32 has a stator-side second positioning hole 32b penetrating at a position facing the second positioning hole 33c.
The first cover 34 has a bottomed cover-side first positioning hole 34b at a position facing the first positioning hole 33b. The second cover 35 has a bottomed cover-side second positioning hole 35b at a position facing the second positioning hole 33c.

  The first positioning pins 44 are fitted into the first positioning holes 31b, 33b, and 34b, and the second positioning pins 45 are fitted into the second positioning holes 32b, 33c, and 35b. Are arranged in phase with each other. For this reason, the two stators 31 and 32 can be aligned with each other by a simple positioning operation with a very simple configuration. In addition, the presence or absence of alignment by the positioning pins 44 and 45 is arbitrary.

The electric motor 10 may have the following modified example. That is, the electric motor 10 may be arranged such that the phases of the plurality of rotors 22 and 23 coincide with each other and the phases of the plurality of stators 31 and 32 may be shifted from each other as shown in FIG.
FIG. 6 is a view showing a modification of the stator block shown in FIG. 5, in which each part of the stator block 30 shown in FIG. 5 is viewed from the motor axial direction. FIG. 6A shows the first stator 31. FIG. 6B shows the inter-stator spacer 33. FIG. 6C shows the second stator 32.

As shown in FIG. 6, the first and second stators 31 and 32 are arranged out of phase with each other by an angle θ2. That is, the phase of the second stator 32 is shifted from the reference 0 ° in the clockwise direction by the angle θ2 with respect to the first stator 31. The angle θ2 is 7.5 ° as described above.
In the first stator 31, one winding 38 is disposed at a reference position of 0 °, and another winding 38 is sequentially disposed in the clockwise direction. In the second stator 32, one winding 38 is arranged at a position shifted in phase by an angle θ2 clockwise from the reference 0 °, and another winding 38 is arranged in order clockwise.

More specifically, in the inter-stator spacer 33, the phase of the second positioning hole 33c is shifted from the reference 0 ° in the clockwise direction by an angle θ2 with respect to the first positioning hole 33b.
Further, the inter-stator spacer 33 has twice as many bolt holes 33a as the embodiment shown in FIG. The phase of the plurality of bolt holes 33a is in a position shifted in phase by an angle θ2 clockwise from the position of each bolt hole 33a shown in FIG.

The first stator 31 has four first positioning holes 31b. The four first positioning holes 31b are arranged one by one at the positions of 0 ° and 180 °, and are also arranged one by one at the positions whose phases are shifted counterclockwise by the angle θ2.
Further, the first stator 31 has twice as many bolt holes 31a as the embodiment shown in FIG. The phases of the plurality of added bolt holes 31a are at positions shifted in phase by an angle θ2 counterclockwise from the positions of the bolt holes 31a shown in FIG.

The second stator 32 has four first positioning holes 32b. The four first positioning holes 32b are arranged one by one at the positions of 0 ° and 180 °, and are also arranged one by one at the positions whose phases are shifted by the angle θ2 in the clockwise direction.
Further, the second stator 32 has twice as many bolt holes 32a as the embodiment shown in FIG. The phases of the plurality of added bolt holes 32a are at positions shifted in phase by an angle θ2 clockwise from the positions of the respective bolt holes 32a shown in FIG.

As shown in FIGS. 2, 5, and 6, the first positioning pins 44, 44 are fitted into the two first positioning holes 33b, 33b, respectively, and the second positioning holes 33c, 33c are respectively second positioned. By fitting the pins 45, 45, the two stators 31, 32 are arranged out of phase with each other.
As described above, according to the modification, the plurality of stators 31 and 32 can have the same configuration, so that productivity is increased.

  By the way, as shown in FIG.1 and FIG.3, the electric motor 10 is provided with the phase detection sensor 50 for detecting the phase of each rotor 22,23. The phase detection sensor 50 includes a sensor rotor 51 disposed on an end face of the flange 21c of the motor shaft 21 and three detection elements 52, 53, and 54 that magnetically detect the phase of the sensor rotor 51. The sensor rotor 51 has a plurality of permanent magnets (for example, eight in accordance with the arrangement of the permanent magnets 26 of the rotors 22 and 23) arranged at an equal pitch around the motor shaft 21. The three detection elements 52, 53, and 54 are arranged radially at an equal pitch around the motor shaft 21, and are composed of, for example, a Hall IC.

  Next, a self-propelled snowplow equipped with the traveling electric motor 10 will be described with reference to FIGS. For convenience, the left member of the left and right members is denoted by L, and the right member is denoted by R. The same applies to the traveling electric motor 10.

FIG. 7 is a side view of the self-propelled snowplow according to the present invention. FIG. 8 is a schematic plan view and control system diagram of the self-propelled snowplow shown in FIG.
As shown in FIGS. 7 and 8, a self-propelled snowplow 100 includes an auger-type snow removal work device 102, an engine 103 that drives the snow removal work device 102, and crawler-type left and right travel devices. 104L, 104R and left and right traveling electric motors 10L, 10R for driving only the left and right traveling devices 104L, 104R are provided. Furthermore, the machine body 101 includes a battery 105 and left and right operation handles 106L and 106R extending from the rear part to the rear upper part. The left and right operation handles 106L and 106R have grips 107L and 107R at the tips, respectively.

  Such a self-propelled snow remover 100 is said to be an auger-type snow remover because it scrapes and removes snow with the auger 123 at the front while traveling forward. An operator can steer the self-propelled snowplow 100 with the operation handles 106L and 106R while walking with the self-propelled snowplow 100.

  The left and right traveling devices 104L and 104R are configured to be driven only by the traveling electric motors 10L and 10R. The left and right crawler belts 111L and 111R and the left and right driving wheels (traveling wheels) 112L and 112R and left and right rolling wheels 113L and 113R arranged at the rear. The left crawler belt 111L is driven via the left drive wheel 112L by the torque generated by the left electric motor 10L. The right crawler belt 111R is driven via the right drive wheel 112R by the torque generated by the right electric motor 10R.

The snow removal work device 102 includes an auger housing 121, a blower case 122 integral with the back surface of the auger housing 121, an auger 123 provided in the auger housing 121, a blower 124 provided in the blower case 122, and a shooter 125 (see FIG. 7).
The engine 103 is a snow removal drive source that drives the snow removal work device 102 via the electromagnetic clutch 126. The power of the engine 103 is transmitted to the auger 123 and the blower 124 via the electromagnetic clutch 126 and the auger transmission shaft 127. The snow scraped by the auger 123 can be blown away by the blower 124 via the shooter 125.

  The left operation handle 106L includes a travel preparation lever 131. The travel preparation lever 131 is a travel preparation member that acts on the switch 131a, and the switch 131a is turned off when the free spring shown in the drawing is brought about by the pulling action of the return spring. When the travel preparation lever 131 is grasped with the left hand of the operator, the switch 131a is turned on.

An operation panel 132 and a control unit 133 are disposed between the left and right operation handles 106L and 106R. As shown in FIG. 8, the operation panel 132 includes a main switch 134, an auger switch 135, a forward / reverse speed operation unit 136, and left and right turning operation switches 137L and 137R.
The engine 103 can be started by turning the main switch 134 on. The auger switch 135 is a manual switch that switches the electromagnetic clutch 126 on and off, and includes, for example, a push button switch.

  The forward / reverse speed operation unit 136 is an operation unit for controlling the rotation of the left and right electric motors 10L and 10R. The operation lever 136a swings back and forth, and an operation signal corresponding to the swing amount of the operation lever 136a. And a potentiometer 136b. The control unit 133 performs traveling control as follows according to the operation of the forward / reverse speed operation unit 136.

  When the operation lever 136a is in the neutral position, the left and right traveling devices 104L and 104R are stopped by stopping the rotation of the left and right electric motors 10L and 10R. When the operation lever 136a is swung forward from the neutral position, the left and right traveling motors 104L and 104R are moved forward by causing the left and right electric motors 10L and 10R to rotate forward. When the operation lever 136a is swung backward from the neutral position, the left and right traveling devices 104L and 104R are moved backward by reversing the left and right electric motors 10L and 10R. By controlling the rotational speeds of the left and right electric motors 10L and 10R according to the swing amount of the operation lever 136a, the traveling speeds of the left and right traveling devices 104L and 104R are controlled. Thus, the front and rear direction and the high / low speed control can be set by one operation lever 136a.

  The left and right turning operation switches 137L and 137R are push button switches, and are contact automatic return type switches that are switched on and generate a switch signal only while the push button is pressed.

Next, the control system of the self-propelled snow blower 100 will be described with reference to FIG. The control system of the self-propelled snow blower 100 is integrated with the control unit 133 as the center. The control unit 133 has a built-in memory, and appropriately reads and controls various types of information stored in the memory.
The generator 141 is rotated by a part of the output of the engine 103, and the obtained electric power is supplied to the battery 105 and supplied to the left and right electric motors 10L and 10R and other electric components. The remaining output of the engine 103 is used to rotate the auger 123 and the blower 124.
The battery 105 supplies power to the left and right electric motors 10L and 10R and other electrical components. For this reason, even when the engine 103 is stopped, the left and right electric motors 10L and 10R can be driven to drive the self-propelled snowplow 100.

  By grasping the travel preparation lever 131 and turning on the auger switch 135, the electromagnetic clutch 126 can be connected (turned on), and the auger 123 and the blower 124 can be rotated by the power of the engine 103. By turning off the auger switch 135, the electromagnetic clutch 126 can be turned off. The electromagnetic clutch 126 can be disengaged by either setting the travel preparation lever 131 free or turning the auger switch 135 off.

Next, the traveling system will be described.
Self-propelled snow blower 100 includes left and right electromagnetic brakes 142L and 142R as brakes corresponding to parking brakes for ordinary vehicles. These electromagnetic brakes 142L and 142R are in a brake state (on state) under the control of the control unit 133 during parking.

  The control unit 133 which has obtained the position information of the operation lever 136a of the forward / reverse speed operation unit 136 from the potentiometer 136b issues a control signal to the left and right driver circuits 143L and 143R, and the drive current required for the left and right electric motors 10L and 10R. To rotate the left and right electric motors 10L, 10R. Further, the control unit 133 detects the rotation speeds of the electric motors 10L and 10R with the motor rotation sensors 144L and 144R, and performs feedback control so that the rotation speed becomes a predetermined value based on the detection signals. As a result, the left and right drive wheels 112L and 112R rotate in a desired direction at a predetermined speed and enter a traveling state.

  The drive control system for the left and right electric motors 10L, 10R may be, for example, a pulse width modulation system (PWM system) that supplies a pulse voltage to the motor terminals. In the case of the PWM method, the driver circuits 143L and 143R emit pulse signals whose pulse widths are controlled in accordance with the control signal of the control unit 133 to control the rotation of the electric motors 10L and 10R.

The drive currents individually supplied from the left and right driver circuits 143L and 143R to the left and right electric motors 10L and 10R are detected by current sensors 145L and 145R.
The voltage of the battery 105 (terminal voltage) is detected by the battery voltage sensor 146.

  Braking while driving is performed according to the following procedure. The left and right driver circuits 143L and 143R include a regenerative brake circuit. By supplying electric energy from the battery to the electric motor, the electric motor rotates. On the other hand, a generator is a means for converting rotation into electrical energy. Therefore, in the present invention, the electric motor is changed to a generator by electrical switching to generate power. If the generated voltage is higher than the battery voltage, electrical energy can be stored in the battery. This is the operating principle of the regenerative brake.

  While the left turning operation switch 137L is being turned on, based on the on signal, the control unit 133 activates the left regenerative brake circuit to reduce the speed of the left electric motor 10L. While the right turning operation switch 137R is being turned on, based on the on signal, the control unit 133 activates the right regenerative brake circuit to reduce the speed of the right electric motor 10R. That is, the self-propelled snow blower 100 turns left only while operating the left turning operation switch 137L. In addition, the self-propelled snow blower 100 turns right only while operating the right turning operation switch 137R.

  Next, in the control system diagram of the self-propelled snowplow 100 shown in FIG. 8, the relationship among the control unit 133, the left driver circuit 143L, and the left electric motor 10L will be described in detail with reference to FIG. explain. The same applies to the right driver circuit 143R and the right electric motor 10R, and the description thereof will be omitted.

  As shown in FIG. 9, the electric motor 10 </ b> L (that is, the electric motor 10 shown in FIG. 1) has twelve windings 38 for each of the stators 31 and 32. A plurality of winding phases 61 to 63 are configured by connecting 12 windings 38 in series, for example, four adjacent to each other. Specifically, there are three winding phases: a U-phase winding phase 61, a V-phase winding phase 62, and a W-phase winding phase 63. These winding phases 61 to 63 are arranged in the circumferential direction of the stators 31 and 32. As described above, the plurality of winding phases 61 to 63 is an aggregate of the plurality of windings 38. The plurality of winding phases 61 to 63 are connected in Y connection (star connection) by connecting one ends thereof. As described above, the plurality of stators 31 and 32 have the windings 38 that are electrically independent for each of the stators 31 and 32.

  The left driver circuit 143L includes a first driver circuit 71 that supplies a drive current to the winding phases 61 to 63 of the first stator 31 and a second driver circuit that supplies a drive current to the winding phases 61 to 63 of the second stator 32. The driver circuit 72 is included. The first driver circuit 71 includes three phase drivers, a U-phase driver 74, a V-phase driver 75, and a W-phase driver 76, which are independent of each other. The same applies to the second driver circuit 72.

  Here, a configuration including a combination of the first rotor 22 and the first stator 31 is referred to as a first motor unit 81. A configuration including a combination of the second rotor 23 and the second stator 32 is referred to as a second motor unit 82.

  Further, a configuration including a combination of the electric motor 10, a left driver circuit 143L that supplies a drive current to the electric motor 10, and a control unit 133 that controls the left driver circuit 143L is referred to as a power unit 90. .

  Next, among the circuits shown in FIG. 9, the relationship among the control unit 133, the first driver circuit 71, and the first stator 31 will be described in detail with reference to FIG. Since the second driver circuit 72 and the second stator 32 are the same, description thereof is omitted. In FIG. 10, + Vcc is the positive electrode of the battery 105.

As shown in FIG. 10, in the first driver circuit 71, the three phase drivers 74 to 76 have the same configuration. That is, the U-phase driver 74 is formed of a half bridge circuit in which an upper element 74a and a lower element 74b are connected in series, and the connection point is connected to the U-phase winding phase 61, for example. The U-phase driver 74 has two current regeneration diodes 74c and 74d.
The V-phase driver 75 includes, for example, a half bridge circuit in which an upper element 75a and a lower element 75b are connected in series, and a connection point thereof is connected to a V-phase winding phase 62. The V-phase driver 75 has two current regeneration diodes 75c and 75d.
The W-phase driver 76 includes, for example, a half-bridge circuit in which an upper element 76a and a lower element 76b are connected in series, and a connection point thereof is connected to a W-phase winding phase 63. The W-phase driver 76 has two current regeneration diodes 76c and 76d.

  The drivers 71 and 72 are not limited to half-bridge circuits, and may be H-bridge circuits, for example. The upper elements 74a, 75a, and 76a and the lower elements 74b, 75b, and 76b are made of transistors, for example.

Next, torque ripple generated by the electric motor 10 will be described.
First, torque generated by the first motor unit 81, that is, torque generated on the first winding side will be described based on FIG. 11 with reference to FIG.

FIG. 11 is a characteristic diagram showing characteristics on the first winding side (first motor unit 81) with the horizontal axis as the rotation angle of the first rotor and the vertical axis as the signal and torque of each part.
The first stator 31 has twelve windings 38. For this reason, the number of times of switching the current of the entire 12 windings 38 is 24 times. That is, every time the first rotor 22 rotates 15 °, the current of the 12 windings 38 is switched. FIG. 11 shows the characteristics of each part when the rotation angle of the first rotor 22 is every 15 °.

Here, the output signal of the first Hall IC (detection element) 52 in the phase detection sensor 50 is Hu, the output signal of the second Hall IC (detection element) 53 is Hv, and the output signal of the third Hall IC (detection element) 54. Is Hw.
In the first driver circuit 71, the input signal of the upper element 74a is Uu, the input signal of the upper element 75a is Vu, the input signal of the upper element 76a is Wu, the input signal of the lower element 74b is Ud, and the input signal of the lower element 75b is Vd. The input signal of the lower element 76b is Wd.
On the first winding side, the drive current supplied to the U-phase winding phase 61 is Iu, the drive current supplied to the V-phase winding phase 62 is supplied to Iv, and the W-phase winding phase 63 is supplied. The drive current is Iw.
H is a high level signal and L is a low level signal. In the driving current, + is a positive current and-is a negative current.

As shown in FIG. 11, the waveforms of the output signals generated by the three Hall ICs 52 to 54 are shifted in phase by 30 ° of the rotation angle of the first rotor 22. For this reason, the waveforms of the drive currents supplied to the three winding phases 61 to 63 are shifted in phase by 30 ° of the rotation angle of the first rotor 22. As a result, it can be seen that the first rotor 22 on the first winding side generates torque at every rotation angle of 15 °. As it is, the peak value of the torque generated by the first rotor 22 is relatively large.
In order to suppress vibration of the electric motor 10 and output torque from the electric motor 10 efficiently, it is preferable to suppress torque ripple.

  Next, the torque generated by the first rotor 22 on the first winding side (first motor unit 81) and the torque generated by the second rotor 23 on the second winding side (second motor unit 82) The combined torque will be described based on FIG. 12 with reference to FIGS. 4 and 6.

In the electric motor 10, the phases of the first and second rotors 22 and 23 are shifted from each other by the angle θ 2, and the phases of the first and second stators 31 and 32 are in agreement with each other. Alternatively, in the electric motor 10, the phases of the first and second rotors 22 and 23 coincide with each other, and the phases of the first and second stators 31 and 32 are shifted from each other by an angle θ2.
Since the current of the 12 windings 38 is switched every time the first rotor 22 rotates 15 °, the value of θ2 is set to 7.5 °. The result is shown in FIG.

FIG. 12 is a torque characteristic diagram showing the combined torque, where the horizontal axis is the rotation angle of the first and second rotors and the vertical axis is the generated torque.
According to FIG. 12, when the first and second rotors 22 and 23 rotate by the rotation angle θ2 after the first winding side generates torque (θ2 = 7.5 °), the second winding side It turns out that torque is generated. That is, the timing for generating torque is shifted between the first winding side and the second winding side. As a result, the combined torque of the torque generated on the first winding side and the torque generated on the second winding side (generated torque of the entire electric motor 10) generates a torque for each rotation angle θ2.

  As a result, the phase of each torque ripple generated for each of the motor units 81 and 82 including a combination of one rotor and one stator can be shifted. For this reason, the torque ripple of the entire electric motor 10 can be easily suppressed. That is, the torque generated by the electric motor 10 can be smoothed. In addition, in order to suppress the torque ripple, the plurality of rotors 22 and 23 arranged with the phases shifted from each other are fixed to one motor shaft 21 or the phases of the plurality of stators 31 and 32 are shifted with respect to each other. Easy configuration.

Next, a control flow when the control unit 133 shown in FIGS. 8 and 9 is a microcomputer will be described based on FIGS. 13 to 14 with reference to FIG.
However, in the case of the configuration of the control flow shown in FIGS. 13 to 14, the electric motor 10 is configured as follows. That is, the plurality of rotors 22 and 23 are arranged in phase with each other, and the plurality of stators 31 and 32 are also arranged in phase with each other.

These control flows are started when the main switch 134 is turned on, for example. In the figure, STxx indicates a step number. Step numbers that are not specifically described proceed in numerical order.
In addition, regarding the following control flow, the relationship among the control unit 133, the left driver circuit 143L, and the left electric motor 10L will be described in particular. Since the same applies to the right driver circuit 143R and the right electric motor 10R, the description thereof is omitted.

FIG. 13 is a control flowchart (first embodiment) of the control unit according to the present invention.
ST01: The drive current Imr supplied from the driver circuit 143L to the electric motor 10L is detected by the current sensor 145L.
ST02: It is checked whether or not the drive current Imr is lower than a predetermined reference current Ims. If YES, the process proceeds to ST03, and if NO, the process proceeds to ST04. Here, the reference current Ims is a drive current required when the self-propelled snowplow 100 is caused to travel without performing snow removal work by the snow removal work device 102.

  ST03: YES, so the light load control mode is selected from the plurality of control modes stored in the control unit 133. The light load control mode is a control mode in which the driver circuit 143L is controlled so that a drive current is supplied only to a predetermined winding 38 among the plurality of windings 38. For example, a drive current is supplied only to each winding 38 in one of the first and second stators 31 and 32.

ST04: Since NO, the normal control mode is selected from the plurality of control modes stored in the control unit 133. The normal control mode is a control mode in which the driver circuit 143L is controlled so as to supply drive current to all the windings 38.
ST05: After controlling the driver circuit 143L based on the control mode selected in ST03 or ST04, the control in this control flow is terminated.

As described above, in the first embodiment shown in FIG. 13, when the self-propelled snowplow 100 is driven without performing the snow removal work by the snow removal work device 102, the load applied to the electric motors 10L and 10R is small. As a result, the drive current Imr supplied to the electric motors 10L and 10R is lower than the reference current Ims.
When the control unit 133 that executes the control of the control flowchart shown in FIG. 13 determines that the condition that the drive current Imr supplied to the electric motor 10L is lower than the predetermined reference current Ims (ST02). The plurality of driver circuits 71 and 72 are controlled so that the drive current is supplied only to the predetermined winding 38 in the plurality of windings 38 (ST03, ST05). As a result, the torque generated by the electric motors 10L and 10R is small.

  On the other hand, when the self-propelled snowplow 100 is run while performing snow removal work by the snow removal work device 102, the load applied to the electric motors 10L and 10R is large. As a result, the drive current Imr supplied to the electric motors 10L and 10R reaches the reference current Ims. At this time, for example, the control unit 133 may perform control so as to supply drive current to all the windings 38 (ST04, ST05). As a result, the torque generated by the electric motors 10L and 10R is large. Moreover, the electric motors 10L and 10R can be rotated at a low speed according to the speed operation of the operator.

  Thus, since the supply of the drive current to the electric motors 10L and 10R is only changed depending on the presence or absence of the snow removal work by the snow removal work device 102, the power consumption of the electric motors 10L and 10R can be suppressed with a simple configuration. it can.

Furthermore, the electric motor 10 includes one motor shaft 20, a plurality of rotors 22 and 23, and a plurality of stators 31 and 32. The windings 38 of the stators 31 and 32 are electrically independent for each of the stators 31 and 32. The driver circuits 71 and 72 are divided into a plurality of parts so as to individually supply a driving current for each winding 38 of the stators 31 and 32. The plurality of driver circuits 71 and 72 can be individually controlled by the control unit 133.
For this reason, the current supply capability of each of the driver circuits 71 and 72 can be small. Each driver circuit 71 and 72 can be reduced in size.

  The driver circuits 71 and 72 generate heat. On the other hand, since the driver circuits 71 and 72 are divided into a plurality of parts, the heat radiation from the driver circuits 71 and 72 can be dispersed. For this reason, the heat sink for cooling each driver circuit 71 and 72 can be reduced in size. Therefore, the power unit 90 can be reduced in size.

  Furthermore, since the driver circuits 71 and 72 are divided into a plurality of parts, the control unit 133 can individually control the plurality of driver circuits 71 and 72 in accordance with a change in the load applied to the electric motor 10. That is, the drive current is supplied only to the necessary winding 38. As a result, wasteful current consumption (driving current) by the electric motor 10 can be easily suppressed to save energy. Moreover, the power unit 90 can be simply configured.

FIG. 14 is a control flowchart (second embodiment) of the control unit according to the present invention.
ST11: Various signals are read.
ST12: It is checked whether or not the snow removal operation is stopped. If YES, the process proceeds to ST13, and if NO, the process proceeds to ST15. For example, when the auger switch 135 is off, it is determined that “snow removal work is stopped”.

  ST13: It is checked whether or not a traveling operation has been performed. If YES, the process proceeds to ST14. If NO, the control in this control flow is terminated. For example, when the operation lever 136a is swinging forward or backward (when it is tilted), it is determined that “the driving operation has been performed”.

  ST14: The light load control mode is selected from the plurality of control modes stored in the control unit 133. The light load control mode is a control mode in which the driver circuit 143L is controlled so that a drive current is supplied only to a predetermined winding 38 among the plurality of windings 38. For example, a drive current is supplied only to each winding 38 in one of the first and second stators 31 and 32.

ST15: It is checked whether or not a traveling operation has been performed. If YES, the process proceeds to ST16, and if NO, the control in this control flow is terminated.
ST16: The normal control mode is selected from the plurality of control modes stored in the control unit 133. The normal control mode is a control mode in which the driver circuit 143L is controlled so as to supply drive current to all the windings 38.
ST17: After controlling the driver circuit 143L based on the control mode selected in ST14 or ST16, the control in this control flow is terminated.

As described above, in the second embodiment shown in FIG. 14, when the self-propelled snow remover 100 is run without performing the snow removal work by the snow removal work device 102, the load applied to the electric motors 10L and 10R is small. As a result, the drive current Imr supplied to the electric motors 10L and 10R is lower than the reference current Ims.
The control unit 133 that executes the control of the control flowchart shown in FIG. 14 includes a condition that the snow removal work by the snow removal work device 102 is stopped (ST12) and a condition that the travel devices 111L and 111R are operated (ST13). ), The plurality of driver circuits 71 and 72 are controlled so as to supply the drive current only to the predetermined winding 38 in the plurality of windings 38 (ST14, ST14). ST17). As a result, the torque generated by the electric motors 10L and 10R is small.

  On the other hand, when the self-propelled snowplow 100 is run while performing snow removal work by the snow removal work device 102, the load applied to the electric motors 10L and 10R is large. As a result, the drive current Imr supplied to the electric motors 10L and 10R reaches the reference current Ims. At this time, for example, the control unit 133 may perform control so as to supply drive current to all the windings 38 (ST16, ST17). As a result, the torque generated by the electric motors 10L and 10R is large. Moreover, the electric motors 10L and 10R can be rotated at a low speed according to the speed operation of the operator.

  Thus, since the supply of the drive current to the electric motors 10L and 10R is only changed depending on the presence or absence of the snow removal work by the snow removal work device 102, the power consumption of the electric motors 10L and 10R can be suppressed with a simple configuration. it can.

  Furthermore, since the driver circuits 71 and 72 are divided into a plurality of parts, the control unit 133 can individually control the plurality of driver circuits 71 and 72 in accordance with a change in the load applied to the electric motor 10. That is, the drive current is supplied only to the necessary winding 38. As a result, wasteful current consumption (driving current) by the electric motor 10 can be easily suppressed to save energy. Moreover, the power unit 90 can be simply configured.

  Next, modified examples of the traveling electric motor 10, the control unit 133, and the driver circuit 143L will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected about the structure similar to the electric motor 10, the self-propelled snow remover 100, the control part 133, and driver circuit 143L which are shown in FIGS.

  FIG. 15 is a cross-sectional view of a traveling electric motor according to a modified example of the present invention, and is shown in accordance with FIG. A traveling electric motor 10A according to a modified example is a brushless inner rotor type DC motor including a rotor block 20A and a stator block 30A.

  The rotor block 20A includes one motor shaft 21A and one rotor 22A. The rotor 22A is an annular member fixed to the motor shaft 21A, for example, by press fitting, and has substantially the same configuration as the first rotor 22 shown in FIGS. However, the rotor 22 </ b> A is longer than the first rotor 22 so as to correspond to all of the plurality of stators 31, 32, 39. For this reason, the length of the plurality of permanent magnets 26A is set to be large corresponding to the length of the rotor 22A.

  Next, the stator block 30A will be described. The stator block 30A includes three stators 31, 32, 39, two inter-stator spacers 33, 33, and two covers 34, 35. The three stators 31, 32, and 39 are annular outer stators that are divided into a plurality of members in the axial direction of the motor shaft 21A and arranged to individually correspond to one rotor 22A. The three stators 31, 32, 39 are arranged in phase with each other.

  The rotor 22A and the stators 31, 32, 39 are arranged concentrically with respect to the motor shaft 21A. The rotor 22A is disposed with a slight gap (air gap) inside the corresponding stator 31, 32, 39.

Thus, the electric motor 10A according to the modification includes one motor shaft 21A, one rotor 22A provided on the motor shaft 21A, and three stators arranged in the motor shaft direction corresponding to the rotor 22A. The brushless inner rotor type DC motor is composed of 31, 32, and 39.
The rotor block 20A has substantially the same configuration as the rotor block 20 shown in FIGS. 1 to 4 except that there is only one rotor 22A.
The stator block 30A has substantially the same configuration as the stator block 30 shown in FIGS. 1 to 4 except that the stator block 30A has a third stator 39 in addition to the first stator 31 and the second stator 32. is there.

Next, the relationship among the control unit 133, the left driver circuit 143L, and the left electric motor 10A in the modification will be described in detail with reference to FIG.
Here, as shown in FIG. 16, a configuration including a combination of the rotor 22 </ b> A and the first stator 31 is referred to as a first motor unit 81 </ b> A. A configuration including a combination of the rotor 22A and the second stator 32 is referred to as a second motor unit 82A. A configuration including a combination of the rotor 22A and the third stator 39 is referred to as a third motor unit 83A.

  Further, a configuration including a combination of the electric motor 10A, a driver circuit 143L that supplies a driving current to the electric motor 10A, and a control unit 133 that controls the driver circuit 143L is referred to as a power unit 90A.

  The electric motor 10 </ b> A has twelve windings 38 for each of the stators 31, 32, and 39. A plurality of winding phases 61 to 63 are configured by connecting 12 windings 38 in series, for example, four adjacent to each other. Specifically, there are three winding phases: a U-phase winding phase 61, a V-phase winding phase 62, and a W-phase winding phase 63. These winding phases 61 to 63 are arranged in the circumferential direction of the stators 31, 32 and 39. Thus, the plurality of winding phases 61 to 63 are aggregates of the plurality of windings 38 and are electrically independent from each other. The plurality of winding phases 61 to 63 are connected in Y connection (star connection) by connecting one ends thereof.

  The modified driver circuit 143 </ b> L includes a third driver circuit 73 in addition to the first driver circuit 71 and the second driver circuit 72. Similarly to the first driver circuit 71, the third driver circuit 73 includes three phase drivers of a U-phase driver 74, a V-phase driver 75, and a W-phase driver 76 that are independent of each other. That is, the third driver circuit 73 has substantially the same configuration as the first driver circuit 71.

Next, a control flow when the control unit 133 shown in FIG. 16 is a microcomputer will be described based on FIG. 17 with reference to FIG. These control flows are started when the main switch 134 (see FIG. 8) is turned on, for example. In the figure, STxx indicates a step number. Step numbers that are not specifically described proceed in numerical order.
However, in the case of the configuration of the control flow shown in FIG. 16, the electric motor 10A is configured as follows. That is, the plurality of stators 31, 32, 39 are arranged in phase with each other.

FIG. 17 is a control flowchart of the control unit according to the modified example of the invention.
ST21: Regenerative braking operation signals, that is, switch signals of the left and right turning operation switches 137L and 137R are read.
ST22: It is checked whether or not a regenerative braking operation is performed. If YES, the process proceeds to ST23, and if NO, the process returns to ST21. When the left turning operation switch 137L or the right turning operation switch 137R is turned on, it is determined that the regenerative braking operation has been performed.
ST23: The voltage Ebr of the battery 105 is detected by the battery voltage sensor 146.
ST24: A regenerative current Irr flowing from the electric motor 10L to the battery 105 via the driver circuit 143L is detected by the current sensor 145L.

ST25: Check whether the voltage Ebr of the battery 105 exceeds a predetermined reference voltage Ebs set in advance. If YES, the process proceeds to ST26, and if NO, the process proceeds to ST28. The voltage Ebr increases according to the remaining amount of the battery 105. The reference voltage Ebs is set to a value that prevents overcharging of the battery 105 (for example, a voltage in a state where the battery 105 is nearly fully charged).
ST26: Check whether the regenerative current Irr exceeds a predetermined reference regenerative current Irs set in advance. If YES, the process proceeds to ST27, and if NO, the process proceeds to ST28. The reference regenerative current Irs is set to the maximum regenerative current (charging current) in consideration of the durability of the battery 105.

ST27: The unbalanced regeneration control mode is selected from the plurality of control modes stored in the control unit 133.
The unbalanced regenerative control mode is a mode for controlling the three driver circuits 71 to 73 so that the three motor units 81A, 82A, and 83A generate uneven torque during regenerative braking. The control unit 133 controls the three driver circuits 71 to 73 so as to make the distribution of the torque generated by each motor unit 81A, 82A, 83A uneven by executing the unbalanced regeneration control mode. Become. The total torque generated by the three motor units 81A, 82A, 83A, that is, the combined torque, is a torque (necessary torque) required by the control unit 133 for the electric motor 10A. The combined torque in this case is a regenerative torque. An example of the unbalanced regeneration control mode will be described with reference to FIGS.

ST28: The normal regenerative control mode is selected from the plurality of control modes stored in the control unit 133.
The normal regenerative control mode is a mode for controlling the three driver circuits 71 to 73 so that the three motor units 81A, 82A, and 83A generate equal torque during regenerative braking. The control unit 133 controls the three driver circuits 71 to 73 so as to equalize the distribution of torque generated by the motor units 81A, 82A, and 83A by executing the normal regeneration control mode. The total torque generated by the three motor units 81A, 82A, 83A, that is, the combined torque, is a torque (necessary torque) required by the control unit 133 for the electric motor 10A. The combined torque in this case is a regenerative torque. An example of the normal regeneration control mode will be described with reference to FIG.

  ST29: After controlling the driver circuit 143L based on the regeneration control mode selected in ST27 or ST28, the control in this control flow is terminated.

FIG. 18 is an explanatory diagram for explaining an example of the normal regeneration control mode shown in ST28 of FIG. 17, and is represented in the same manner as in FIG. That is, FIG. 18 shows the control characteristics of the motor unit with the horizontal axis as the rotation angle of the rotor and the vertical axis as the signal / torque of each part.
The torque generated by the first motor unit 81A (generated torque on the first winding side) is Tb1. The torque generated by the second motor unit 82A (generated torque on the second winding side) is Tb2. The torque generated by the third motor unit 83A (generated torque on the third winding side) is Tb3. The total sum of the three torques Tb1 to Tb3, that is, the combined torque is Tbt.

First, the first motor unit 81A will be described. At the time of regenerative braking, the control unit 133 sets signals (input signals Uu, Vu, Wu) issued to all the upper elements in the first driver circuit 71 as the low level signal L. For this reason, the generated torque Tb1 on the first winding side has a negative value.
Similarly, the control unit 133 issues the same signal as that of the first driver circuit 71 to the second driver circuit 72 and the third driver circuit 73. For this reason, the generated torque Tb2 on the second winding side and the generated torque Tb3 on the third winding side are also negative values.
The values of the generated torques Tb1, Tb2, Tb3 are the same. The combined torque Tbt is a regenerative torque because it is a negative value obtained by combining Tb1, Tb2, and Tb3.

Thus, according to the normal regenerative control mode, the regenerative torque Tbt requested by the control unit 133 to the electric motor 10A (required regenerative torque Tbt) can be evenly distributed to the three motor units 81A, 82A, 83A. .
The required regenerative torque Tbt is a value calculated by the control unit 133 according to an external condition (for example, a condition for stopping a load driven by the electric motor 10A).

  FIG. 19 is an explanatory diagram (part 1) illustrating an example of the unbalanced regeneration control mode shown in ST27 of FIG. 17, and is represented in the same manner as FIG. That is, FIG. 19 shows the control characteristics of the first motor unit 81A with the horizontal axis as the rotation angle of the rotor and the vertical axis as the signal / torque of each part.

  During regenerative braking, the control unit 133 issues a control signal to the upper element and the lower element in the first driver circuit 71 according to the output signal of the first Hall IC 52. For this reason, the generated torque Tb1 on the first winding side is a positive value.

  FIG. 20 is an explanatory diagram (part 2) illustrating an example of the unbalanced regeneration control mode shown in ST27 of FIG. 17, and is represented in the same manner as in FIG. That is, FIG. 20 shows the control characteristics of the second and third motor units 82A and 83A with the horizontal axis as the rotation angle of the rotor and the vertical axis as the signal / torque of each part.

  At the time of regenerative braking, the control unit 133 sets signals (input signals Uu, Vu, Wu) issued to all upper elements in the second and third motor units 82A, 83A as the low level signal L. For this reason, the second and third generated torques Tb2, Tb3 are negative values.

  The generated torque Tb1 on the first winding side shown in FIG. 19 and the generated torques Tb2 and Tb3 on the second and third winding sides shown in FIG. 20 have the same absolute value. The combined torque Tbt is a negative value obtained by combining Tb1, Tb2, and Tb3. That is, the combined torque Tbt is a regenerative torque.

  Thus, according to the unbalanced regenerative control mode, the regenerative torque Tbt requested by the control unit 133 to the electric motor 10A can be unevenly distributed to the three motor units 81A, 82A, 83A.

Here, the relationship between the generated torques Tb1, Tb2, Tb3 on each winding side and the required regenerative torque Tbt in the unbalanced regeneration control mode is summarized as follows.
The generated torques Tb1, Tb2, and Tb3 on each winding side can be set by multiplying the required regenerative torque Tbt by predetermined coefficients α1, α2, and α3. For example, the coefficient on the first winding side is α1, the coefficient on the second winding side is α2, and the coefficient on the third winding side is α3. As a result, the generated torques Tb1, Tb2, and Tb3 on each winding side are determined by the following equation. As described above, the required regenerative torque Tbt is a negative value.
Tb1 = Tbt × α1
Tb2 = Tbt × α2
Tb3 = Tbt × α3
However, it is a condition that the conditional expression “α1 + α2 + α3 = + 1” is satisfied. For example, α1 = −1, α2 = + 1, and α3 = + 1.

In this way, the generated torque Tb1 on the first winding side is set as the normal rotation driving torque. Further, the generated torques Tb2 and Tb3 on the second and third winding sides are set as regenerative torque.
Tb1 is a positive value, Tb2 and Tb3 are negative values, and the absolute values of all the values are the same. For this reason, the value of Tbt, which is the sum of Tb1, Tb2, and Tb3, is the same regenerative torque as the value of Tb3. The electric motor 10A can be regeneratively braked by this Tbt.

  In addition, by positively setting Tb1, Tb2, and Tb3 to be unbalanced, the torque output to the outside from the electric motor 10A is the same as in the normal regenerative control mode shown in FIG. Moreover, the electric power regenerated by the battery 105 can be reduced.

This will be described in detail as follows. For ease of understanding, only the relationship between torque, current and efficiency will be described.
Here, the efficiency (efficiency at the time of motor driving) when a general electric motor generates driving torque is ηo. The driving torque is proportional to the product of the motor driving current and the efficiency ηo. In other words, the motor drive current is proportional to the product of the drive torque and the inverse of the efficiency ηo (1 / ηo).
In addition, the efficiency when the electric motor generates a regenerative current according to the regenerative torque during regenerative braking (efficiency during regenerative braking) is defined as ηi. The regenerative current is proportional to the product of regenerative torque and efficiency ηi. Note that the efficiency ηi may be considered to be substantially the same as the efficiency ηo.

Incidentally, the efficiency ηtu of the entire motor in the normal regeneration control mode shown in ST28 of FIG. 17 is equal to the efficiency ηi (ηtu = ηi).
On the other hand, in the unbalanced regeneration control mode shown in ST27 of FIG. 17, the motor driving current I1 on the first winding side is proportional to the product of the driving torque and the reciprocal of the efficiency ηo (1 / ηo). The regenerative current I2 on the second winding side is proportional to the product of the regenerative torque and the efficiency ηi. The regenerative current I3 on the third winding side is also proportional to the product of the regenerative torque and the efficiency ηi.

  As a matter of course, the driving torque is a positive value and the regenerative torque is a negative value. The motor drive current I1 is a positive value, and the regenerative currents I2 and I3 are negative values. Since the regenerative torque of the entire motor is a negative value, the regenerative current It of the entire motor is a negative value obtained by the expression “It = I1 + I2 + I3”. Therefore, the efficiency ηta of the entire motor is obtained by the equation “ηta = 2 × ηi− (1 / ηo)”.

  As is apparent from the above description, the overall motor efficiency ηta in the unbalanced regenerative control mode is smaller than the overall motor efficiency ηtu in the normal regenerative control mode (ηtu> ηta). Therefore, the electric power regenerated by the battery in the unbalanced regenerative control mode is reduced with respect to the electric power regenerated by the battery in the normal regenerative control mode.

As described above, in the modification examples shown in FIGS. 15 to 20, during regenerative braking, the voltage Ebr of the battery 105 exceeds a predetermined reference voltage Ebs (for example, a voltage in a state where the battery 105 is almost fully charged), and When the regenerative current Irr exceeds a predetermined reference regenerative current Irs, the control unit 133 issues different control signals to the plurality of driver circuits 71, 72, 73, respectively.
On the other hand, when the voltage Ebr of the battery 105 does not exceed the predetermined reference voltage Ebs or when the regenerative current Irr does not exceed the predetermined reference regenerative current Irs, the control unit 133 has a plurality of driver circuits 71, 72, 73. To all the same control signals.

  Thus, in order to prevent overcharge of the battery 105 due to regenerative braking when the battery 105 is fully charged, it is only necessary to issue different control signals from the control unit 133 to the driver circuits 71, 72, 73. For this reason, it is not necessary to provide a resistor for flowing a large regenerative current when the battery 105 is fully charged. Therefore, the power unit 90A capable of regenerative braking can be configured simply.

Furthermore, the electric motor 10A includes one motor shaft 21A, at least one rotor 22A, and a plurality of stators 31, 32, and 39. The winding 38 of each stator 31, 32, 39 is electrically independent for each stator 31, 32, 39. The driver circuits 71, 72, 73 are divided into a plurality so as to individually supply a drive current for each winding 38 of the stators 31, 32, 39. The plurality of driver circuits 71, 72, 73 can be individually controlled by the control unit 133.
Therefore, the current supply capability of each driver circuit 71, 72, 73 can be small. Each driver circuit 71, 72, 73 can be reduced in size.

  The driver circuits 71, 72, 73 generate heat. On the other hand, since the driver circuits 71, 72, 73 are divided into a plurality of parts, the heat radiation from the driver circuits 71, 72, 73 can be dispersed. For this reason, the heat sink for cooling each driver circuit 71, 72, 73 can be reduced in size. Therefore, the power unit 90A can be reduced in size.

Next, a modification of the self-propelled snowplow 100 shown in FIGS. 7 and 8 will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the structure similar to the electric motor 10 and self-propelled snowplow 100 shown in FIGS. 1-14, and the description is abbreviate | omitted.
FIG. 21 is a side view showing a modification of the self-propelled snowplow according to the present invention.
The deformable self-propelled snow removal machine 200 is configured to drive only the dozer-type snow removal device 202, the crawler-type left and right traveling devices 204L and 204R, and the left and right traveling devices 204L and 204R. Left and right traveling electric motors 10L and 10R are provided.

The airframe 201 includes a traveling frame 201A having traveling devices 204L and 204R and traveling electric motors 10L and 10R on the left and right sides, and a vehicle body frame 201B attached to the rear part of the traveling frame 201A so as to be able to swing up and down.
The vehicle body frame 201B includes a battery 205 and left and right operation handles 206L and 206R extending from the rear part to the rear upper part. The left and right operation handles 206L and 206R have grips 207L and 207R at the tips, respectively.
An expansion / contraction mechanism 251 is interposed between the rear portion of the traveling frame 201A and the rear portion of the vehicle body frame 201B.

The snow removal work device 202 is composed of a dozer (snow drainage member) that pushes snow forward. The battery 205 corresponds to the battery 105 shown in FIG.
The left and right traveling devices 204L and 204R are configured to be driven only by the traveling electric motors 10L and 10R. The left and right crawler belts 211L and 211R and the left and right driving wheels (traveling wheels) 212L and 212R and left and right rolling wheels 213L and 213R arranged at the rear. The left crawler belt 211L is driven via the left drive wheel 212L by the torque generated by the left electric motor 10L. The right crawler belt 211R is driven via the right drive wheel 212R by the torque generated by the right electric motor 10R.

  Such a self-propelled snow remover 200 is said to be a dozer-type snow remover because it scrapes and removes snow with a front dozer while traveling forward. An operator can steer the self-propelled snowplow 200 with the operation handles 206L and 206R while walking with the self-propelled snowplow 200.

One of the left and right operation handles 206 </ b> L and 206 </ b> R includes a height adjusting lever 252. Only when the operator holds the height adjustment lever 252, the telescopic mechanism 251 contracts, so that the vehicle body frame 201B swings upward with respect to the rear portion of the traveling frame 201A. As a result, the snow removal work device 202 swings upward.
Thereafter, when the operator releases his / her hand from the height adjusting lever 252, the telescopic mechanism 251 extends, and the vehicle body frame 201B swings downward with respect to the rear portion of the traveling frame 201A. As a result, the snow removal work device 202 swings downward.
When the snow removal work device 202 is lowered to the snow-removable position shown in FIG. 21, the lower end position sensor 253 issues an ON signal.

  An operation panel 232 and a control unit 233 are disposed between the left and right operation handles 206L and 206R. The operation panel 232 includes a main switch 234 and a forward / reverse speed operation unit 236. The main switch 234 corresponds to the main switch 134 shown in FIG. The forward / reverse speed operation unit 236 corresponds to the forward / reverse speed operation unit 136 shown in FIG.

  The control unit 233 corresponds to the control unit 133 shown in FIG. In addition, the presence or absence of the left and right turning operation switches 137L and 137R and the left and right electromagnetic brakes 142L and 142R shown in FIG. 8 is arbitrary. The other members shown in FIG. 8 are also provided in the self-propelled snowplow 200 of the modified example.

  In the embodiment of the present invention, the electric motors 10 and 10A are not limited to the inner rotor system, but may be an outer rotor system.

  The electric motors 10, 10A correspond to one motor shaft 21, 21A, at least one rotor 22, 23, 22A provided on the motor shaft 21, 21A, and the rotor 22, 23, 22A. What is necessary is just the structure which consists of several stators 31, 32, 39 arranged in the motor axial direction.

  In addition, the electric motor 10 is not limited to the configuration in which the plurality of windings 38 are provided in the stators 31 and 32, but may be configured in the rotors 22 and 23. The electric motor 10A according to the modified example is not limited to the configuration in which the plurality of windings 38 are provided in the stators 31, 32, and 39, and may be configured in the rotor 22A. In that case, a plurality of permanent magnets 26 may be provided in each of the stators 31, 32, 39.

In addition, the control unit 133 and the left and right driver circuits 143L and 143R may be incorporated in any one of them.
Moreover, the structure which drives a some traveling apparatus by one electric motor 10 and 10A is included.

  The electric motors 10 and 10A of the present invention are suitable for being mounted on the self-propelled snow blowers 100 and 200.

It is sectional drawing of the electric motor which concerns on this invention. It is sectional drawing which looked at the electric motor shown by FIG. 1 from the motor axial direction. It is sectional drawing of the rotor block shown by FIG. It is the figure which looked at each part of the rotor block shown by FIG. 3 from the motor axial direction. It is sectional drawing of the decomposition | disassembly state of the stator block shown by FIG. It is the figure which looked at each part of the stator block shown by FIG. 5 from the motor axial direction. It is a side view of the self-propelled snowplow carrying the electric motor shown in FIG. FIG. 8 is a schematic plan view and control system diagram of the self-propelled snowplow shown in FIG. 7. FIG. 9 is a circuit diagram of a control unit, a left driver circuit, and a left electric motor in the control system of the self-propelled snowplow shown in FIG. 8. It is a circuit diagram of the power plant concerning the present invention. It is a characteristic view which shows the characteristic by the side of the 1st winding shown by FIG. It is a torque characteristic figure which shows the synthetic | combination torque of the electric motor shown by FIG. FIG. 10 is a control flowchart (first embodiment) of the control unit shown in FIG. 9. FIG. FIG. 10 is a control flowchart (second embodiment) of the control unit shown in FIG. 9. FIG. It is sectional drawing of the electric motor for driving | running | working of the modification which concerns on this invention. It is a circuit diagram of the power plant of the modification concerning the present invention. It is a control flowchart of the control part shown by FIG. It is explanatory drawing explaining an example of the normal regeneration control mode shown by FIG. It is explanatory drawing (the 1) explaining an example of the unbalance regeneration control mode shown by FIG. It is explanatory drawing (the 2) explaining an example of the unbalance regeneration control mode shown by FIG. It is a side view which shows the modification of the self-propelled snow remover which concerns on this invention.

Explanation of symbols

  10, 10A, 10L, 10R ... electric motor for traveling, 21, 21A ... motor shaft, 22 ... first rotor, 22A ... rotor, 23 ... second rotor, 31 ... first stator, 32 ... second stator, 38 ... Winding, 39 ... third stator, 61, 62, 63 ... winding phase, 81, 81A ... first motor unit, 82, 82A ... second motor unit, 83A ... third motor unit, 90, 90A ... power unit DESCRIPTION OF SYMBOLS 100 ... Self-propelled snow removal machine 101 ... Airframe 102 ... Snow removal work apparatus, 104L, 104R ... Traveling apparatus, 105 ... Battery, 133 ... Control part, 143L, 143R ... Driver circuit, Ebr ... Battery voltage, Ebs ... Reference voltage, Imr ... drive current, Ims ... reference current, Irr ... regenerative current, Irs ... reference regenerative current.

Claims (4)

In a self-propelled snowplow equipped with a snow removal work device such as an auger or a dozer, a traveling device such as a crawler or a wheel, and an electric motor for traveling for driving only the traveling device,
The traveling device is configured to be driven only by the traveling electric motor,
The electric motor for traveling includes a motor shaft, a rotor provided on the motor shaft, and a stator disposed so as to correspond to the rotor.
One of the rotor and the stator is divided into a plurality of members in the motor axial direction,
The self-propelled snow remover characterized in that the plurality of divided members have electrically independent windings for each of the divided members.   A plurality of driver circuits that individually supply a drive current to each of the divided windings of each member; and a control unit that controls the electric motor for traveling by issuing a control signal to the plurality of driver circuits. The self-propelled snow blower according to claim 1, wherein:   When it is determined that the drive current supplied to the electric motor for traveling is less than a predetermined reference current, the control unit determines a predetermined winding in the divided winding of each member. The self-propelled snowplow according to claim 2, wherein the plurality of driver circuits are controlled so as to supply a drive current only to the line.   When the control unit determines that two conditions are satisfied, that is, a condition that the snow removal work by the snow removal work device is stopped and a condition that the travel device is operated, the division is performed. The self-propelled snowplow according to claim 2, wherein the plurality of driver circuits are controlled so that a driving current is supplied only to a predetermined winding in the winding of each member.

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