JPH04111263U - DC motor - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to reduce costs by simplifying the shape of the mold by simplifying the shape of the housing, and to reliably manufacture the housing by resin molding. [Structure] In a DC motor, a rotor is rotatably provided inside a housing 1, and a commutator 4 provided on the rotor projects outside the housing 1. A guide piece 6 is provided to guide the brush 7 that comes into sliding contact with the commutator 4, and a spring 7 is provided that holds the brush 7 so that it does not come off the guide piece 6 and urges the brush 7 against the commutator 4. It has a configuration that allows it to be installed.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a DC motor, and more specifically to a retaining structure for a brush that slides into contact with a commutator. It is something to do.

0002

[Conventional technology]

A conventional brush mounting structure is shown in FIG. There is a recess on the outside of the resin housing 20. A rotor (not shown) is rotatably disposed inside the housing 20. It is set up. A commutator 22 provided on the rotor is connected to the housing 20. It protrudes into the recess 21 through the communication hole 23. Moreover, inside the recess 21 Two fitting pins 24 are integrally formed on the periphery of the communication hole 23. This mating pin 24 each have a brass leaf spring 25 which is curved so as to bend toward the communication hole 23 side. The leaf springs 25 are mounted so that the tips of the leaf springs 25 face each other. stop A brush 26 is provided at the tip of each of the leaf springs 25 so as to be in sliding contact with the outer peripheral surface of the commutator 22. is fixed.

0003 However, in this structure, when the elastic force of the leaf spring 25 decreases, the commutator 22 This makes it impossible to bring the brush 26 into contact with a stable biasing force. Also, brush 26 When the brush 26 is worn out, the biasing force of the leaf spring 25 decreases, and the brush 26 is forced against the commutator 22. Sliding force is unstable. Therefore, in order to always stabilize the sliding contact force of the brush 26 against the commutator 22, As shown in 10, the brush 26 can be loosely inserted into the recess 21 of the resin housing 20. A hollow rectangular brush accommodating portion 27 to be inserted into the brush is integrally formed. And figure 11. As shown in FIG. 12, a support pin provided on one side of the brush storage section 27 One end of the coiled spring 29, which is rotatably wound around the coil spring 28, is attached to the side surface of the recess 21, and the other end is attached to the brush. By bringing the coiled spring 29 into contact with the base end surface of the brush 26, the biasing force of the coiled spring 29 is applied to the brush 26. give. As a result, the tip surface of the brush 26 in the brush storage recess 21 is always kept safe. The commutator 22 is brought into contact with the outer circumferential surface of the commutator 22 with a predetermined biasing force.

0004

[Problem that the idea aims to solve]

However, the resin housing 20 with which the brush storage section 27 is integrated is made of gold. It is formed by molding. Therefore, a mold is used to form the brush storage portion 27. There is a problem that the shape to be formed becomes complicated, leading to an increase in cost. Also, the mold Because of the complexity, even if resin is poured into the mold, the entire inside of the mold may not be filled with resin. There are cases where Therefore, in particular, the brush storage portion 27 may be formed due to insufficient resin filling. The problem is that it disappears.

[0005] This invention was devised to solve the above problems, and its purpose is to By simplifying the shape of the zinc, we can simplify the shape of the mold and reduce costs. We provide DC motors whose housings can be reliably manufactured using resin molding. It's about doing.

[0006]

[Means to solve the problem]

In order to solve the above problems, this invention has a rotor rotatable inside the housing. The DC motor is In the commutator, there is a gas on the outside of the housing that guides the brush that comes into sliding contact with the commutator. providing a guide portion and holding the brush so that it does not come off from the guide portion; In addition, it is possible to attach a fixing member that urges the brush against the commutator. The summary is as follows.

[0007]

[Effect]

Therefore, according to the present invention, the guide member provided outside the housing allows the brush to be The fixing member prevents the brush from shifting laterally, and the fixing member helps hold the brush against the outer circumferential surface of the commutator. Biasing can be performed. Therefore, the shape of the housing can be simplified. At the same time, the fixing member allows the brush to be always urged against the outer circumferential surface of the commutator. Wear.

[0008]

【Example】

An embodiment embodying the present invention will be described below with reference to FIGS. 1 to 5. As shown in Figures 1 and 2, the housing 1 of the DC motor is made of resin. A concave portion 2 having a planar oval shape is integrally formed on the outside thereof. Said recess A communication hole 3 is transparently provided in the bottom surface of the housing 1. A commutator 4 of a rotor (not shown), which is arranged so that it can be inserted, protrudes into the recess 2. Ru. There are inserts on both sides (longitudinal direction in FIG. 2) of the communication hole 3 at the bottom of the recess 2. An inlet hole 5 is bored in the left-right direction. Moreover, between each insertion hole 5 and the communication hole 3, A pair of guide pieces 6 as guide parts are integrally formed so as to face each other in the longitudinal direction. There is. A brush 7 is slidably disposed between the pair of guide pieces 6, and It is held and fixed by a spring 8 as a fixing member fitted into each insertion hole 5. It is. The pair of guide pieces 6 are arranged to prevent the brush 7 from shifting laterally. At the same time, the brush 7 is guided toward the commutator 4 side.

[0009] As shown in FIG. 5, on both sides of the tip of the spring 8 there is a curved elastic shape. The holding pieces 9a and 9b are bent, and the gap between the holding pieces 9a and 9b is At the tip of the pull 8, an elastic biasing piece 10 is located further than the holding pieces 9a and 9b. It is formed by being bent. Then, as shown in FIG. 4, the base end of the spring 8 is press-fitted into each insertion hole 5. ing. The pair of holding pieces 9a, 9b of this spring 8 is biased by its urging force. The brush 7 is held between the guide pieces 6 by pressing the upper surface of the brush 7. Also, spring 8 The biasing piece 10 biases the proximal end surface of the brush 7 with its biasing force, and it to urge the brush 7 toward the commutator 4, and bring the tip of the brush 7 into contact with the outer peripheral surface of the commutator 4. I'm letting you touch me.

0010 In this state, voltage is applied to the pigtails 11 provided on each brush 7. The rotor (not shown) is rotated by applying can be done. Next, the operation of the DC motor configured as described above will be explained. First, a resin housing 1 shown in FIG. 2 is manufactured by integral molding. this At this time, the recess 2, the pair of guide pieces 6, and the insertion hole 5 are also formed at the same time. And how A rotor is disposed within the ring 1, and the commutator 4 of the rotor is connected through the communication hole 3. and protrude into the recess 2. After that, the pigtail 11 is connected between the pair of guide pieces 6. The connected brushes 7 are respectively arranged.

[0011] Next, the base end of the spring 8 is press-fitted into the insertion hole 5. At this time, the base of the brush 7 In order to bring the biasing piece 10 into contact with the end face, the biasing piece 10 is bent to connect with the spring 8. In addition to reducing the interval, the retaining pieces 9a and 9b of the spring 8 hold the brush 7. Press the base end of the spring 8 into the insertion hole 5 so that the upper surface is held by the biasing force. do.

0012 Then, the biasing piece 10 of the spring 8 biases the base end surface of the brush 7, and the brush 7 is biased. The brush 7 moves toward the commutator 4 along between the pair of guide pieces 6, and the tip surface of the brush 7 is aligned. It comes into contact with the outer peripheral surface of the flow child 4. Also, the brush is held by the holding pieces 9a and 9b of the spring 8. 7 is held between the guide pieces 6. In this state, by applying voltage to the pigtail 11, the brush 7 is adjusted. The rotor can be rotated via the flow child 4. At this time, attach the spring 8. Since the brush 7 is urged by the urging force of the force piece 10, the brush 7 is always aligned with a constant force. It can be brought into contact with the outer peripheral surface of the flow child 4. As a result, the brush 7 is in contact with the commutator 4. It is possible to prevent the biasing force from changing even if it is worn away due to friction. Furthermore , since the upper surface of the brush 7 is urged by the holding pieces 9a and 9b of the spring 8, the brush 7 is The brush 7 can be prevented from coming off from between the pair of guide pieces 6.

[0013] Also, the brush 7 tends to shift laterally due to the rotation of the commutator 4, but the pair of guide pieces 6 can prevent the brush 7 from shifting laterally. And replace brush 7 When performing maintenance, etc., remove the spring 8 from the insertion hole 5 and remove the brush. 7 can be taken out, making maintenance easy. Therefore, unlike the conventional case, the recess 2 of the housing 1 is formed to fix the brush 7. The insertion hole 5 and the guide piece 6 are simply formed by unevenness, so the mold shape is simplified. This makes it easier to manufacture the mold, and it is possible to reduce the cost of manufacturing the mold. In addition, since the housing 1 has a simple shape, resin is poured into a mold and the housing is When forming the ring 1, the insertion hole 5 and guide piece 6 may be formed due to insufficient resin filling. It is possible to prevent this from occurring.

[0014] In this embodiment, guide pieces are provided on both sides of the brush 7 (in the left-right direction in FIG. 2). 6 are provided respectively to prevent the brush 7 from shifting laterally, and to connect the brush 7 to the commutator 4. As shown in Fig. 6, the guide part has a triangular cross section. A pair of guide rails 12a and 12b are integrally formed on the bottom surface of the recess 2, as shown in FIG. A guide groove 1 is formed on the bottom surface of the brush 7 along the guide rails 12a and 12b so that It is also possible to form 3a and 13b respectively.

[0015] As with the guide piece 6, this prevents the brush 7 from shifting laterally. , it can be slid toward the commutator 4 side. Furthermore, as shown in FIG. 8, the upper surfaces of the guide rails 12a and 12b are shaped flat. The guide grooves 13a and 13b of the brush 7 can be formed according to this shape. It is possible.

[0016]

[Effect of the idea]

As detailed above, according to the present invention, the mold can be reduced by simplifying the shape of the housing. In addition to simplifying the shape and reducing costs, the housing is made securely by resin molding. It has an excellent effect of being able to be molded.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view showing a brush holding structure for a DC motor according to the present invention.

FIG. 2 is a partially cutaway perspective view showing a state in which an insertion hole and a guide piece are integrally formed in a recessed portion of the housing.

FIG. 3 is a partially cutaway front view showing a brush disposed between a pair of guide pieces.

FIG. 4 is a partially cutaway perspective view showing a state in which the brush is biased by the biasing piece of the spring and the tip end surface of the brush is in contact with the outer circumferential surface of the commutator.

FIG. 5 is an enlarged perspective view showing the shape of a spring.

FIG. 6 is a partially cutaway perspective view showing another example in which a guide rail is integrally formed in a recessed portion of the housing.

FIG. 7 is an enlarged perspective view showing a state in which guide grooves are formed on the bottom surface of the brush.

FIG. 8 is a partially cutaway perspective view showing another example in which a guide rail is integrally formed in a recessed portion of the housing.

FIG. 9 is a partially cutaway perspective view showing a conventional brush holding structure.

FIG. 10 is a partially cutaway perspective view showing a brush storage portion formed in a recess of a conventional housing.

FIG. 11 is a plan view showing a conventional brush holding structure.

FIG. 12 is an enlarged partially cutaway perspective view showing a conventional brush holding structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Housing, 4... Commutator, 6... Guide piece as a guide part, 7... Brush, 8... Spring as a fixing member, 12a, 12b... Guide rail as a guide part

Claims (1)

[Scope of utility model registration request] 1. A DC motor in which a rotor is rotatably provided inside a housing, and a commutator provided on the rotor projects outside the housing, wherein the commutator is in sliding contact with the outside of the housing. D characterized in that a guide part for guiding the brush is provided, and a fixing member that holds the brush so that it does not come off from the guide part and biases the brush against the commutator can be attached.
C motor.