JP5112200B2 - Wiper motor - Google Patents

Description

  The present invention relates to a multipolar motor having four or more poles capable of switching operations at two speeds or more, and more particularly to a motor used for a drive source of a vehicle wiper device.

  2. Description of the Related Art Conventionally, as a drive source for a vehicle wiper device such as an automobile, a brushed DC motor that has a large starting torque and can obtain a large torque at a high load has been widely used. Such a wiper motor often employs a three-brush structure capable of switching between two speeds on the motor side in accordance with the low speed / high speed operation (HI / LOW) mode of the wiper device. FIG. 11 is an explanatory diagram showing a brush arrangement configuration of a wiper motor capable of switching between two speeds.

As shown in FIG. 11, the conventional wiper motor is provided with three brushes: a common brush 51 a (−), a low speed (LOW) brush 51 b (+), and a high speed (HI) brush 51 c (+). The high speed brush 51c is disposed at a position advanced from the low speed brush 51b. For example, Japanese Patent Laid-Open No. 2002-315274 discloses a wiper motor having a similar three-brush structure, and the two-speed operation of the wiper device is realized by switching the brush to be used in accordance with the driver switching. Yes. Japanese Utility Model Laid-Open No. 7-28756 discloses a wiper apparatus using a wiper motor having a three-brush structure that realizes an intermediate speed mode between a low speed and a high speed by means of control.
JP 2002-315274 A Japanese Utility Model Publication No. 7-28756 JP 2000-166185 A Japanese Patent Laid-Open No. 3-11963 JP 2001-95219 A JP 2001-112217 A JP 2002-17061 A JP 2002-58227 A JP 2002-218692 A JP 2002-233123 A JP 2002-305861 A JP 2004-56851 A JP 2004-274816 A Japanese Patent Laid-Open No. 2004-274821 JP 2004-289992 A

  On the other hand, conventional wiper motors are mainly two-pole motors that are structurally simple. At present, there are few multi-pole motors having four or more poles in the market. On the other hand, in recent years, adoption of a 4-pole motor capable of reducing the size and thickness of cores, magnets, yokes, and the like has been studied in response to demands for reducing the size and weight of wiper motors. However, if two-speed switching is to be realized with a motor with four-pole winding specifications, as shown in FIG. 12, two sets of common / low-speed / high-speed brushes are required, for a total of six brushes (51a, 51a ′, 51b, 51b ′, 51c, 51c ′) must be arranged. When the number of brushes increases in this way, the product cost increases and the brushes are close to each other, which is not preferable in terms of component layout. For this reason, in response to the demand for reduction in size and weight, there has been a problem that how to reduce the size of the four-pole motor has become the center of product development.

  The object of the present invention is to realize a switching operation of two or more speeds while suppressing an increase in the number of brushes in a 4-pole double winding type wiper motor, to reduce the size and weight of the motor, to reduce the cost, and to improve the layout. The goal is to improve.

The wiper motor of the present invention is used as a drive source of a vehicle wiper device, and includes four field magnetic poles fixed to the inner peripheral surface of a motor housing, and an armature in which armature windings are wound in multiple turns. the armature winding is a plurality arranged commutator segments which are electrically connected along the circumferential direction, and arranged commutator to the armature, the co-when placed in approximately 90 ° intervals, The first and second brushes that are in contact with the surface of the commutator and energized during low-speed operation, and the first and second brushes that are in contact with the surface of the commutator and energized during high-speed operation together with one of the first and second brushes A third brush for speed change, a plurality of coils connected between adjacent commutator pieces and forming the armature winding, and an average connecting the coils to be equipotential among the coils. a wiper motor comprising comprises a member, the The wiper motor is provided with only the three brushes of the first to third brushes as brushes that are in sliding contact with the surface of the commutator and feed power to the coil, and the third brush and the first brush. Of the space formed between the second brush and the second brush, the first brush and the third brush are arranged in a wide-angle space so as to face the first and second brushes. It has arrange | positioned in the position pressed from three directions .

  In the present invention, by using the pressure equalizing member, it is possible to reduce the brushes of the same potential that should originally exist at the opposed positions of the first to third brushes, while realizing two speeds in the multipolar motor. The number of brushes can be reduced. For this reason, although the number of motors is increased, there is no increase in cost due to an increase in the number of brushes, and there is no increase in loss around the brushes. Further, there is no problem of close arrangement of brushes. Therefore, two-speed operation such as HI and LO can be realized without greatly increasing the number of brushes while enjoying the advantages of miniaturization and weight reduction by the multipolar machine.

  In the multipolar motor, a brush that contacts the surface of the commutator is additionally arranged in at least one position that is advanced or retarded in the motor rotation direction with reference to the position facing the first to third brushes. May be. In this way, by utilizing the space that is vacated by the use of the pressure equalizing member and adding the brush, for example, three speeds including the MID mode and the super LOW mode can be realized. In other words, new operation modes other than HI and LO operation can be realized without significantly increasing the number of brushes in multipolar machines, and various operation modes can be achieved while reducing the size and weight of conventional two-pole machines. Can be provided.

  According to another multi-pole motor of the present invention, the first and second multi-pole motors having four or more field magnetic poles and having the armature winding wound in multiple windings are used during low-speed operation. A second brush and a third brush used at the time of high-speed operation together with any one of the first and second brushes and a plurality of coils connected between adjacent commutator pieces to form an armature winding Among them, a pressure equalizing member that connects coils that should be equipotential is provided, so that the number of brushes facing at the same potential can be reduced, and the number of brushes can be reduced while realizing two speeds in a multipolar motor. It becomes possible. For this reason, it becomes possible to suppress the cost increase accompanying the increase in the number of brushes and the increase in the loss around the brush, and the problem of the proximity of the brush is solved. Therefore, it is possible to realize the two-speed operation such as HI, LO, etc. without greatly increasing the number of brushes while enjoying the advantages of reduction in size and weight due to the multipolar machine.

  Further, in the multipolar motor, a brush can be added using a space vacated by the use of a pressure equalizing member, and an advance angle in the motor rotation direction with respect to a position facing the first to third brushes, or By additionally arranging the brush at at least one of the retarded positions, for example, an operation mode of 3 speeds or more with MID mode, super LOW mode, or the like is possible. Therefore, even in multi-pole machines, new operation modes other than HI and LO operation can be realized without significantly increasing the number of brushes, and various operation modes can be achieved while reducing the size and weight of conventional two-pole machines. Can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view illustrating a configuration of a wiper motor that is Embodiment 1 of the present invention. The wiper motor 1 is used as a drive source for an automobile wiper device, and includes a motor unit M and a deceleration unit R that decelerates the rotational output of the motor unit M. As shown in FIG. 1, the motor unit M has a configuration in which an armature 3 is rotatably disposed in a bottomed cylindrical motor housing 2. Two to four permanent magnets (field magnetic poles) 4 are fixed to the inner peripheral surface of the motor housing 2 in the circumferential direction, and the wiper motor 1 is configured with four poles by the permanent magnets 4.

  The armature 3 includes an armature core 6 fixed to the rotating shaft 5 and an armature coil (armature winding) 7 wound around the armature core 6. The left end portion of the rotating shaft 5 in the figure is rotatably supported by a bearing 8 attached to the motor housing 2, and the armature 3 is rotatably mounted in the motor housing 2. The armature core 6 is configured by laminating a plurality of ring-shaped metal plates 9 and is fixed to the rotating shaft 5. A slot 11 is recessed along the axial direction on the outer periphery of the armature core 6. A winding 12 is wound between the slots 11 with multiple windings. An armature coil 7 is formed on the outer periphery of the armature core 6 by the winding 12.

  A commutator 13 is disposed adjacent to one end side of the armature core 6. The commutator 13 is externally fixed to the rotating shaft 5. A plurality of commutator pieces (commutator pieces) 14 formed of a conductive material are attached to the outer peripheral surface of the commutator 13. The commutator piece 14 is made of a plate-like metal piece that is long in the axial direction, and is fixed in parallel along the circumferential direction while being insulated from each other. A riser 15 is formed at the end of each commutator piece 14 on the armature core 6 side. A winding 12 serving as a winding start end and a winding end end of the armature coil 7 is wound around the riser 15 and fixed by fusing. Thereby, the commutator piece 14 and the armature coil 7 corresponding to this are electrically connected.

  A gear housing 16 made of aluminum die cast that constitutes the speed reduction portion R is attached to the opening end of the motor housing 2. A holder stay 17 is attached to the inside of the left end of the gear housing 16 in the drawing. As shown in FIG. 2, the holder stay 17 is provided with two pairs of brush holders 18 opposed to each other at four locations in the circumferential direction, and the motor unit M has a 4-parallel circuit 4-brush configuration. The brush holder 18 is internally provided with brushes 19 (19a to 19d) that can be moved in and out. In each brush 19, the brushes 19a and 19c and the brushes 19b and 19d have the same polarity (19a, 19c: +, 19b, 19d :-), respectively.

The protruding tip (inner diameter side tip) of each brush 19 is in sliding contact with the commutator 13, and the brush 19 is pressed against the commutator 13 by a spring 21. A pigtail 22 is attached to each brush 19 and is electrically connected to a power source (not shown) via the pigtail 22. The commutator 13 is supplied with electric power from an external power source via a pigtail 22 and a brush 19. The right end portion of the rotating shaft 5, the worm wheel 23, and the like are accommodated in the gear housing 16 of the speed reduction portion R. A bearing 24 that rotatably supports the central portion of the rotating shaft 5 is fixed in the gear housing 16. A worm 25 is formed at the tip of the rotating shaft 5, and the worm 25 meshes with the worm wheel 23. The worm wheel 23 is fixed to the output shaft 26. When the motor unit M operates and the rotary shaft 5 rotates, the rotation is transmitted from the worm 25 to the worm wheel 23, and the output shaft 26 rotates. The output shaft 26 is connected to a wiper arm via a link mechanism (not shown), and the wiper arm performs a predetermined wiping operation as the output shaft 26 rotates.

  In the wiper motor 1 having such a configuration, the MID mode having an intermediate speed in addition to the two speeds of HI and LOW is formed by switching each brush 19 as follows. That is, the wiper motor 1 realizes three modes of “normal operation (low speed) —medium speed—high speed” with the four brushes 19 a to 19 d. 3A is an explanatory diagram showing the brush configuration of the wiper motor 1, FIG. 3B is a list showing the energizing brushes in each mode, and FIG. 4 is an explanatory diagram showing the brush energizing state in each mode.

  As shown in FIG. 2 and FIG. 3A, the brush 19 of the wiper motor 1 has four brushes 19a to 19d arranged at equal intervals at 90 ° intervals. Here, the brush 19a (the first positive electrode 1) Brush (+) is defined as + (1), 19b (negative electrode first brush) as − (1), 19c (positive electrode second brush) as + (2), and 19d (negative electrode second brush) as − (2). In this case, in the LOW mode, both the switches SW1 and SW2 in FIG. 4A are turned off, and + (1) and − (1) are energized as shown in FIGS. 3B to 3A. That is, + (1) and-(1) are connected to the power supply side, and only a pair of brushes are used. Therefore, the amount of supplied current is limited and the motor rotation speed is lower than when two pairs of brushes are used together (HI mode described later).

  Next, in the HI mode, as shown in FIG. 4C, both the switches SW1 and SW2 are turned on, and four brushes + (1), + (2),-(1), and-(2) are provided. Are all energized (FIGS. 3B to 3C). In this way, when two pairs of four brushes facing each other are energized, the amount of supplied current increases and the motor rotation speed is higher than when a pair of brushes (+ (1),-(1)) is energized. Become. On the other hand, in the MID mode newly established in the wiper motor 1, as shown in FIG. 4B, the switch SW1 remains OFF and the SW2 is turned ON, and + (1),-(1), and-(2) are energized. (FIGS. 3B to 3B). That is, three of the four brushes 19a to 19d are used, and the amount of supply current is larger than when a pair of brushes (+ (1),-(1)) is used, but two pairs This is less than when both brushes are used. Therefore, in this case, the motor speed is intermediate between the LOW mode and the HI mode.

  As described above, in the wiper motor 1, the motor rotation speed can be changed from low speed to medium speed to high speed by controlling the energization states of the four brushes 19a to 19d as shown in FIG. That is, although the motor is a 4-pole motor, the motor speed can be switched to 2 speeds or more with four brushes. Therefore, HI and LO operation can be realized without significantly increasing the number of brushes even in a multi-pole machine, and the MID mode not found in conventional wiper motors can be achieved while enjoying the advantages of small size and light weight. It becomes possible to add. In addition, intermittent operation can be performed in each mode of HI, MID, and LOW, and a total of six modes of operation can be realized.

  On the other hand, when the control mode as shown in FIG. 3B is adopted, in the LOW mode with the highest use frequency, the combination of energizing + (1) and-(1) is obtained. However, when + (1) and-(1) are energized, as shown in FIG. 4A, the winding lengths of the parallel circuits differ between the brushes and become electrically unbalanced, and + (2 ),-(2), the armature coil 7 short-circuited is not arranged symmetrically with respect to the rotating shaft 5 and is unbalanced magnetically. Therefore, in the wiper motor 1, in order to eliminate such magnetic imbalance, individual coils connected between adjacent commutator pieces 14 are formed by a plurality of subcoils arranged symmetrically with respect to the rotation axis. Employs a linear configuration to improve motor durability.

  FIGS. 5A to 5D are winding development views showing examples of the above-described winding forms. In the form of winding shown in FIG. 5A, the winding 12 is wound in two at the opposing position of the armature core 6. That is, in FIG. 5A, for example, the winding 12 started to be wound from the third commutator piece 14c is suspended around the riser 15 of the third commutator piece 14c, and then the slot 11a between the first and second teeth. And a slot 11e between the 5th and 6th teeth, and a coil 7A (subcoil) is formed. The coil 7A is wound around (n / 2) times the predetermined number n of turns in the armature coil 7.

  Thereafter, the coil 7A is opposed to the slots 11e and 11a in the radial direction, that is, the slot 11k between the slots 11k and 15-16 which are present at a position rotated by 180 ° in the circumferential direction. The coil 7B (subcoil) is formed. The coil 7B is wound in the same direction as the coil 7A by a half number (n / 2) of the predetermined number of turns n, and then the winding 12 is connected to the fourth commutator piece 14d. Thereby, between the 3rd and 4th commutator pieces 14c and 14d, the armature coil 7 provided with a pair of coils 7A and 7B opposed to each other in the radial direction and connected in series is formed. Similarly, between the adjacent commutator pieces 14, an armature coil 7 including a pair of coils 7 </ b> A and 7 </ b> B that are opposed to each other in the radial direction and connected in series is formed.

  Next, in the winding form of FIG. 5B, the winding 12 is wound equally in all directions. That is, in FIG. 5 (b), for example, the winding 12 started from the third commutator piece 14c is wound (n / 4) turns between the slots 11a-11e (coil 7A), and then the slot 11e. From the slots 11a and 11e to the slot 11j, and is wound between the slots 11f and 11j at positions shifted by 90 ° in the circumferential direction (coil 7B). Since the coil 7B faces the magnetic pole (permanent magnet 4) having a different polarity from the coil 7A, the winding 12 turns (n / 4) in the winding direction opposite to that between 11a-11e between the slots 11f-11j. Wrapped. Thereafter, the winding 12 is directed from the slot 11f to the slot 11k and between the slots 11k and 11o at a position shifted by 90 ° in the circumferential direction from the slots 11f and 11j (a position opposite to the slots 11a and 11e by 180 °). (Coil 7C; secondary coil). Between the slots 11k-11o, the winding 12 is wound (n / 4) turns in the same winding direction as between 11a-11e.

  After winding between the slots 11k-11o, the winding 12 is further directed from the slot 11o to the slot 11p, and at a position shifted by 90 ° in the circumferential direction from the slots 11k, 11o (opposing 180 ° to the slots 11f, 11j). It is wound between the slots 11p and 11t at the position (coil 7D; secondary coil). Between the slots 11p-11t, the winding 12 is wound (n / 4) turns in a winding direction opposite to that between 11a-11e. The winding 12 is then connected to the fourth commutator piece 14d from the slot 11p. Also in this case, the coils 7 </ b> A to 7 </ b> D are equally arranged symmetrically with respect to the rotating shaft 5, and the armature coil 7 short-circuited by the brush 19 is arranged in a symmetrical positional relationship with respect to the rotating shaft 5.

  In the winding configuration of FIG. 5C, the winding 12 is wound in two at opposite positions of the armature core 6 as in FIG. 5A. Different from (a). Here, the winding 12 started to be wound from the third commutator piece 14c is first wound ((n / 2) -m) times between the slots 11a-11e. Next, the winding 12 is wound (n / 2) turns between the slots 11k and 11o that are radially opposed to the slots 11e and 11a (coil 7B). Thereafter, the winding 12 faces from the slot 11o to the slot 11a, is wound m times between the slots 11a-11e, and is connected to the fourth commutator piece 14d. That is, between the slots 11a-11e, the winding 12 is wound (n / 2) turns together with the previous ((n / 2) -m) turns to form the coil 7A.

  In the winding form of FIG. 5 (d), the winding 12 is equally wound around the four sides as in FIG. 5 (b), but the winding method of the winding 12 is different from that in (c). It has the same form as 5 (c). That is, the winding 12 started to be wound from the third commutator piece 14c is first wound ((n / 2) -m) times between the slots 11a-11e. Next, in the winding 12, the coil 7B is formed between the slots 11f-11j, the coil 7C is formed at the slots 11k-11o, and the coil 7D is formed between the slots 11p-11t in the same manner as in FIG. Thereafter, the coil 12 is wound from the slot 11p toward the slot 11a, m times between the slots 11a-11e, and connected to the fourth commutator piece 14d. That is, between the slots 11a-11e, the winding 12 is wound (n / 2) turns together with the previous ((n / 2) -m) turns to form the coil 7A.

  As described above, when the winding form illustrated in FIG. 5 is employed, the armature coil 7 short-circuited by the brush 19 is always positioned symmetrically with respect to the rotation axis 5 by the coils 7A and 7B (7C and 7D). Placed in a relationship. Therefore, the magnetic imbalance related to the armature coil 7 is eliminated, the magnetic balance is uniform even in the LOW mode, and the durability of the motor is improved. 6A and 6B show the durability test results of the wiper motor 1. FIG. 6A shows the results in the HI mode, and FIG. 6B shows the results in the LOW mode.

  As shown in FIG. 6, when the winding configuration as described above is adopted, the brush wear speed is significantly reduced as compared with the conventional heavy winding. That is, in the HI mode, both the positive electrode and the negative electrode were slightly over 1/4, and in the LOW mode, the positive electrode was about 1/5, 1/7, and the negative electrode was about 1/6, 1/20. Along with this, the durability has also been greatly improved, and it has been greatly improved to about 4.5 times in the HI mode and about 20 times in the LOW mode. The test in FIG. 6 is performed at a high voltage specification (42V), which is a severer condition than the normal voltage (14V specification) of current automotive electrical components, and higher durability is obtained at the normal voltage. It is done. Further, even when the high voltage specification is adopted, it can be seen that the wiper motor 1 has sufficient durability.

  Next, as Embodiment 2 of the present invention, a mode in which the number of brushes is reduced using a pressure equalizing line (pressure equalizing member) will be described. FIG. 7 is an explanatory diagram showing a brush configuration of a wiper motor that is Embodiment 2 of the present invention. The basic configuration of the wiper motor of the present embodiment is the same as that of the wiper motor 1 of the first embodiment shown in FIG. In the following embodiments, the same members and portions as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the wiper motor of this embodiment, the equipotential points of the armature coil 7 are connected by a pressure equalizing line. That is, the opposing coils of the armature coil 7 are connected by a pressure equalizing line. As a result, even if one of the brushes 19 (19p ′, 19q ′, 19r ′) facing at the same potential does not exist, the other brush 19p (the first brush) is applied to the coil fed by these brushes. Electric power is supplied from the brushes, 19q (second brush), and 19r (third brush) through a pressure equalizing line. Therefore, as shown by a broken line in FIG. 7, even if one side (19p ′, 19q ′, 19r ′) of the opposing brush 19 is reduced, there is a reduced brush due to the pressure equalization line. Similarly, power can be supplied to the armature coil 7.

In this embodiment, the brushes 19p and 19q are used in the LOW mode. At this time, power is supplied to the armature coil 7 via the brushes 19p and 19q, but current also flows to the coils to be supplied by the brushes 19p ′ and 19q ′ via the pressure equalizing lines.
Therefore, substantially, the motor is driven in the same state as when the four brushes 19p, 19q, 19p ′, 19q ′ are energized. On the other hand, in the HI mode, the brushes 19q and 19r are used. In this case as well, power is supplied through the brushes 19q and 19r, but current also flows to the coils to be supplied with power by the brushes 19p ′ and 19r ′ through the pressure equalizing lines. Therefore, substantially, the motor is driven in the same state as when the four brushes 19r ′, 19q, 19r, 19q ′ are energized. The brushes 19r and 19r ′ are disposed at positions advanced by (θ / 2) ° with respect to the brushes 19p ′ and 19p, and the motor rotation speed is higher in the HI mode than in the LOW mode.

  In this way, using the pressure equalization line, the number of brushes can be reduced from six to three while realizing two speeds, which is the same number of brushes as the conventional two-pole motor shown in FIG. . For this reason, although the number of motors is increased, there is no increase in cost due to an increase in the number of brushes, and there is no increase in loss around the brushes. Further, it is not necessary to dispose the HI operating brush 19r adjacent to the LOW operating brush 19p ', and the problem of the close placement of the HI and LOW brushes does not occur. Accordingly, HI and LOW operations can be realized without increasing the number of brushes even in a multi-pole machine, and it is possible to achieve a reduction in size and weight with respect to a conventional two-pole machine.

  In addition, by using a pressure equalizing line as in this embodiment, the electrical balance of the armature coil 7 is improved, the whirling force is reduced, and noise and vibration can be reduced. In addition, it is possible to obtain durability that can cope with high voltage. In the conventional two-pole machine shown in FIG. 11, the armature 3 is pushed in the direction shown by the arrow in the figure by the brushes 51a to 51c. On the other hand, in the case of the brush configuration shown in FIG. 7, the armature 3 is pressed from approximately three directions by the brushes 19p, 19q, and 19r. Therefore, compared with the case of FIG. 11, the brush pressing load on the armature 3 is equalized, and the rotation balance of the armature 3 is stabilized.

  Further, as a third embodiment of the present invention, a mode in which an operation mode other than HI and LOW is added to the wiper motor of the second embodiment will be described. FIG. 8A is an explanatory view showing a brush configuration of a wiper motor that is Embodiment 3 of the present invention, and FIG. 8B is a list showing energizing brushes for each mode in the motor of FIG. In the motor shown in FIG. 8, in addition to the brushes 19p, 19q, and 19r shown in FIG. 7, the 19q ′ deleted in the second embodiment is arranged so as to be shifted in the θ ° advance direction, and a brush 19s for HI operation is newly installed. To do. In FIG. 7, the brush 19r is in the HI operation mode, but here, the brush 19r advanced by (θ / 2) ° by providing the HI operation brush 19s advanced by θ is HI, It becomes a brush for MID operation in the middle of LOW.

  As shown in FIG. 8B, in the motor of FIG. 8A, the brushes 19p (+ (1)) and 19q (-(1)) are energized in the LOW mode. As in the case of the second embodiment, the motor is provided with a pressure equalizing line and operates in the same manner as the 4-brush machine with a pair of brushes 19p and 19q although it is a 4-pole machine. Next, in the HI mode, the brushes 19p (+ (1)) and 19s (-(2)) are energized. The brush 19s is provided at a position advanced by θ ° from the position of the brush for operating the LOW (in FIG. 8, the brush itself is omitted by using the pressure equalizing line), and the motor rotates at a higher speed than in the LOW mode. Operates on numbers. In addition, the motor is provided with an MID mode. In this case, the brushes 19r (+ (2)) and 19q (-(1)) are energized. The brush 19r is provided at a position advanced by (θ / 2) ° from the arrangement position of the LOW operation brush (same as above), and the motor operates at an intermediate rotational speed between the LOW mode and the HI mode.

  FIG. 9A is an explanatory diagram showing a modification of FIG. 8, and FIG. 9B is a list showing energizing brushes for each mode. In the case of FIG. 9, both the brushes 19r (+ (2)) and 19s (-(2)) are provided at positions advanced by θ ′ ° from the arrangement position of the LOW operation brush (same as above). In this case, in the LOW mode, the brushes 19p (+ (1)) and 19q (-(1)) are energized as described above. On the other hand, in the HI mode, the brushes 19r (+ (2)) and 19s (-(2)) are energized and an advance angle effect of θ ′ ° is obtained, and the HI mode is more efficient than that of FIG. Is planned. On the other hand, the MID mode has two patterns: brush 19r (+ (2)), 19q (-(1)): MID 1, or brush 19p (+ (1)), 19s (-(2)) : MID 2 is energized, and a rotational speed of (θ ′ / 2) ° advanced is obtained.

  In the form of the present embodiment, in addition to the MID mode, a super-LOW mode that rotates at a lower speed than the LOW mode can be set. FIG. 10A is an explanatory diagram showing a brush configuration when the super LOW mode is set, and FIG. 10B is a list showing energization brushes for each mode in the motor of FIG. In the case of FIG. 10, the brush 19t (+ (2)) is provided at a position that is delayed by θ ° from the arrangement position of the brush for LOW operation. The other brushes are arranged in the same manner as in FIG. In this case as well, the brushes 19p (+ (1)) and 19q (-(1)) are energized in the LOW mode, and the brushes 19p (+ (1)) and 19s (-(2)) are energized in the HI mode. The In contrast, in the super-LOW mode, the brushes 19t (+ (2)) and 19q (-(1)) are energized. The brush 19t is provided at a position that is θ ° retarded (−θ ° advanced) from the position of the LOW actuating brush (same as above), and the motor operates at a lower rotational speed than in the LOW mode.

  As described above, in this embodiment, the space that is vacated by the three-brush configuration of the second embodiment is utilized, and another brush is added thereto, so that the 4-brush configuration is the same as that of the conventional 4-pole machine. Three speeds with MID mode and super LOW mode can be realized. In other words, new operation modes other than HI and LOW operation can be realized without greatly increasing the number of brushes in multipolar machines, and various operation modes can be achieved while reducing the size and weight of conventional two-pole machines. Can be provided.

In Embodiments 2 and 3, a 4-pole machine has been described as an example, but the above-described configuration may be applied to a multi-pole machine having 6 or more poles. For example, if a pressure equalizing line is applied to a 6-pole machine, normally 6 brushes are required, but the LOW mode can be operated with 2 brushes. At this time, there are four spaces where the brushes are originally arranged. Therefore, four types of operation modes other than HI and LOW can be added by appropriately arranging brushes for different operation modes. In other words, as the number of motors increases, the number of types of operation modes can be increased. It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. Yes. For example, the winding form for eliminating the magnetic imbalance is not limited to the example of FIG. 5, and various forms can be adopted. In FIG. 5, the case where the number of turns of the armature coil 7 is an even number is described. However, in the case where the number of turns is an odd number, for example, the number of turns is assigned to the coils 7A and 7B by 0.5 turns. A cancellation winding can be constructed.

  On the other hand, in the above-described embodiment, the case where the motor of the present invention is used as a drive source of an automobile wiper device has been described. However, the application is not limited to this, and a power window motor, a cylindrical fan motor, etc. It can also be applied to motors for OA equipment such as in-vehicle motors and personal computers. In the case of a motor for a power window, for example, it is possible to add a function of slightly opening a window when adjusting the temperature inside the vehicle or smoking in the super LOW mode. In addition, an operation switching function can be added to the fan motor.

It is sectional drawing which shows the structure of the wiper motor which is Example 1 of this invention. It is explanatory drawing which shows the structure of the gear housing left end surface in the wiper motor of FIG. (A) is explanatory drawing which shows the brush structure of the wiper motor of FIG. 1, (b) is a table | surface which shows the electricity supply brush in each mode. It is explanatory drawing which shows the brush electricity supply state in each mode. (A)-(d) is a coil | winding expansion | deployment figure which shows an example of the coil | winding form by this invention. It is the endurance test result of the wiper motor by this invention, (a) shows the result in HI mode, (b) has shown the result in LOW mode. It is explanatory drawing which shows the brush structure of the wiper motor which is Example 2 of this invention. (A) is explanatory drawing which shows the brush structure of the wiper motor which is Example 3 of this invention, (b) is a table | surface which shows the electricity supply brush for every mode in the motor of (a). (A) is explanatory drawing which shows the modification of FIG. 8, (b) is a table | surface which shows the electricity supply brush for every mode in the motor of (a). (A) is explanatory drawing which shows the brush structure at the time of setting super-LOW mode, (b) is a table | surface which shows the electricity supply brush for every mode in the motor of (a). It is explanatory drawing which shows the brush arrangement structure of the conventional wiper motor which can switch 2 speeds. It is explanatory drawing which shows the brush arrangement structure at the time of making the conventional wiper motor into 4 poles.

Explanation of symbols

1 Wiper motor 2 Motor housing 3 Armature 4 Permanent magnet (field magnetic pole)
5 Rotating shaft 6 Armature core 7 Armature coil (armature winding)
7A-7D Coil 8 Bearing
9 metal plate 11 slot 11a, 11e, 11f, 11j, 11o, 11p, 11t slot 12 winding 13 commutator 14 commutator piece (commutator piece)
14c No. 3 commutator piece 14d No. 4 commutator piece 15 Riser 16 Gear housing 17 Holder stay 18 Brush holder 19 Brush 19a Positive first brush 19b Negative first brush 19c Positive second brush 19d Negative second brush 19p, 19p 'Brush 19q, 19q 'Brush 19r, 19r' Brush 19s HI operation brush 19t Super-LOW operation brush 21 Spring 22 Pigtail 23 Worm wheel 24 Bearing 25 Worm 26 Output shaft 51a, 51a 'Common brush 51b, 51b' Low speed brush 51c, 51c 'High speed Brush M Motor part R Deceleration part

Claims (3)

Used as a drive source for vehicle wipers,
A four-pole field magnetic pole fixed to the inner peripheral surface of the motor housing;
An armature in which armature windings are wound with heavy windings;
A plurality of commutator pieces electrically connected to the armature winding are disposed along a circumferential direction, and a commutator disposed in the armature;
Co When placed approximately 90 ° intervals, in contact with the surface of the commutator, and the first and second brushes which are energized during low-speed operation,
A third brush for speed change that contacts the surface of the commutator and is energized during high speed operation together with one of the first and second brushes;
A plurality of coils connected between adjacent commutator pieces to form the armature winding;
A wiper motor comprising a pressure equalizing member that connects between the coils to be equipotential among the coils ,
In the wiper motor, only three brushes of the first to third brushes are provided as brushes that are in sliding contact with the surface of the commutator and supply power to the coil.
The third brush is disposed so as to face the first and second brushes in a wide-angle side space among the spaces formed between the first brush and the second brush, and the first to first brushes. 3. A wiper motor characterized in that three brushes No. 3 are arranged at positions where the commutator is pressed from three directions . 2. The wiper motor according to claim 1, wherein the third brush is disposed in the space on the wide-angle side so that a brush pressing load on the armature is equalized. 3.   3. The wiper motor according to claim 1, wherein the wiper motor is in contact with the surface of the commutator at at least one position advanced or retarded in the motor rotation direction with respect to a position facing the first to third brushes. A wiper motor with an additional brush.

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