CN101607324A

CN101607324A - Cutting machine

Info

Publication number: CN101607324A
Application number: CNA2009101336983A
Authority: CN
Inventors: 古居伸康; 稻垣忠司
Original assignee: Makita Corp
Current assignee: Makita Corp
Priority date: 2008-06-18
Filing date: 2009-04-22
Publication date: 2009-12-23
Also published as: BRPI0904977A2; JP2010000630A

Abstract

The invention provides a kind of cutting machine, it can suppress the sliding-contact part that dust invades commutator and brush effectively.Be formed with the air entry (26,26 of the tempering air of motor (20) in the back of electric machine casing (5) ...), the zone of the upstream side of sliding-contact part in air entry (26), be positioned at commutator (25) and carbon brush (24) along the inflow direction of tempering air is provided with the closure part (27) that stops tempering air to enter from this zone.

Description

Cutting machine

Technical field

The present invention relates to cutting knife cutting by rotating and be cut cutting machines such as the cropper of material or circular saw by motor-driven.

Background technology

As cutting machine, for example patent documentation 1 is disclosed such, known have a kind of following cropper: be arranged on the body of accommodating motor in the housing and possessing discoid cutting knife forwardly on the base of rectangle overlooking down, can be undertaken being cut the cutting of material by the cutting knife that is projected into the base below.In this cropper, form air entry in the back of housing, suck tempering air by the rotation that is arranged on the fan on the output shaft from air entry, discharge from the face side that is arranged on housing, the exhaust outlet of side, realize cooling thus to motor.

[patent documentation 1] TOHKEMY 2006-88559 communique

Under the situation of commutating machine, the back quadrate part in housing contains and is arranged on the brush of the commutator sliding-contact on the output shaft.Thereby, when the air entry of housing back sucks tempering air,, then exist dust to invade the situation of the sliding-contact part of commutator and brush if the dust that produces in operation also together is inhaled into, it is bad to produce rectification thus, shortens brush life.

Summary of the invention

Therefore, the purpose of this invention is to provide and a kind ofly can suppress the sliding-contact part that dust invades commutator and brush effectively, can keep the best rectified action and the cutting machine of brush life.

In order to achieve the above object, the invention of first aspect, it is characterized in that: the zone at the upstream side of sliding-contact part air entry, be positioned at commutator and brush along the inflow direction of tempering air is provided with the closure part that stops tempering air to enter from this zone.

The invention of second aspect is characterized in that: in the invention of first aspect, in order to form the closure part simply, closure part and housing are formed as one.

The invention of the third aspect, it is characterized in that: in the invention of first aspect or second aspect, invade the sliding-contact part of commutator and brush in order more effectively to suppress dust, be formed with tempering air to inclined plane away from the direction guiding of the sliding-contact part of commutator and brush at the tempering air of the closure part end face by side.

According to the invention of first aspect, by adopting the closure part, suppress the sliding-contact part that dust is invaded commutator and brush effectively, can keep best rectified action and brush life.In addition, because the closure part is arranged on the zone of necessary irreducible minimum, so also can suppress the reduction of the cooling effectiveness of motor.

According to the invention of second aspect, except the effect of first aspect, can also by with the integrally formed closure part that forms simply of housing.

According to the invention of the third aspect, except first or the effect of second aspect, can also more effectively suppress the sliding-contact part that dust invades commutator and brush by the inclined plane.

Description of drawings

Fig. 1 is the stereogram of cropper.

Fig. 2 is the rearview of body.

Fig. 3 is the longitudinal section of the back quadrate part of electric machine casing.

Symbol description

1 ... cropper; 2 ... body; 3 ... cutting knife; 4 ... base; 5 ... electric machine casing; 7 ... the blade cover; 10 ... exhaust outlet; 18 ... bearing holder (housing, cover); 20 ... motor; 21 ... output shaft; 23 ... brush carrier; 24 ... carbon brush; 25 ... commutator; 26 ... air entry; 27 ... the closure part; 28 ... the inclined plane;

The specific embodiment

Below, with reference to accompanying drawing embodiments of the present invention are described.

Fig. 1 is the stereogram as the cropper of an example of cutting machine, and cropper 1 is overlooked down on the base 4 of rectangle possesses the body 2 with discoid cutting knife 3.Body 2, in the place ahead of the electric machine casing that bottom tube-like is arranged 5 that contains motor (lower right of Fig. 1 to), the gear housing 6 that connects the tubular that contains reducing gear, the place ahead at this gear housing 6 connects blade cover 7, cutting knife 3 is installed on not shown main shaft outstanding in blade cover 7, is made the below part of cutting knife 3 outstanding to the below of base 4.8 tops that are arranged on body 2 possess the handle of

switch

9,10,10 ... it is the exhaust outlet that between gear housing 6 and blade cover 7, forms.

In addition, a side of body 2 by axle 12 up and down the direction rotation earth's axis be connected on the connecting plate 11, connecting plate 11 can be fixed on position arbitrarily along gathering sill 14 by thumb screw 15, and axle is connected upright be located on the base 4 and has on the fan-shaped guide plate 13 of circular-arc gathering sill 14.On the other hand, distolateral at the opposite side of body 2, similarly circular-arc degree of depth fixator (depth guide) 16 opposed 13 connections of fan-shaped guide plate that are located on the base 4, blade cover 7 is connected on this degree of depth fixator 16 by thumb screw 17.Thus, change link position by thumb screw 17 along degree of depth fixator 16, making body 2 be the center rotation with axle 12, thereby can change the overhang (approach) of the cutting knife of giving prominence to from base 43.In addition,, body 2 is tilted, can change the angle of 3 pairs of bases 4 of cutting knife by the connecting plate 11 in the

guide plate

13,13 that changes both sides and the fixed position of degree of depth fixator 16.

On the other hand, Fig. 2 is the rearview of body 2, Fig. 3 is the longitudinal section of the back quadrate part of electric machine casing 5, and the rear end central authorities in electric machine casing 5 form the bearing holder (housing, cover) 18 of cap shape, forms the maintaining

part

19,19 of tubular respectively at radial direction in the side.The rear end that is housed in the output shaft 21 of the motor 20 in the electric machine casing 5 is bearing on the bearing holder (housing, cover) 18 by 22 on ball bearing, on the other hand, the brush carrier 23 that front end keeps carbon brush 24 is installed on maintaining part 19, under the state that brush carrier 23 is mounted, make carbon brush 24 and commutator 25 butts that are arranged on the output shaft 21.

In addition, in the back of electric machine casing 5, to be equipped with the

apneusis gas port

26,26 on a plurality of left and right directions that make in the electric machine casing 5 with external communications with separating predetermined distance up and down ...Front end at output shaft 21 is provided with not shown fan, fan rotates along with the rotation of output shaft 21, thereby with tempering air from

air entry

26,26 ... suction also passes through in the electric machine casing 5 it, from

exhaust outlet

10,10 ... discharge, can carry out cooling thus motor 20.

But, here, be formed with closure part 27 with bearing holder (housing, cover) 18, this closure part 27 is for

air entry

26,26 ... in, see with the upper right of bearing holder (housing, cover) 18 and everywhere each air entry 26 about the lower-left is corresponding from Fig. 2, from the part of this air entry 26 of periphery shutoff of bearing holder (housing, cover) 18.The point symmetry position of upper right and lower-left that is limited to bearing holder (housing, cover) 18 like this is because of following reason, direction of rotation at this output shaft 21 is seen as right rotation from Fig. 2, tempering air is vortex-like mobile from the rear of electric machine casing 5 along this right rotation direction on one side, be inhaled in the electric machine casing 5 on one side, so the zone of the upstream side of the sliding-contact of shutoff commutator 25 and carbon brush 24 part on this inflow direction realizes stoping tempering air to flow directly into this sliding-contact part thus.

And then, be provided with in the outer end of each closure part 27 along with the tempering air longshore current Inbound outstanding laterally gradually inclined plane 28 of flowing of side (private side of electric machine casing 5) downstream, shown in the arrow of Fig. 3, can the direction of the tempering air guiding on inclined plane 28 away from the sliding-contact part of commutator 25 and carbon brush 24 (away from the direction in the axle center of output shaft 21) will be flow through.

In the cropper 1 that constitutes as described above, base 4 is being placed under the state that is cut on the material, if pressing operation switch 9 and drive motors 20, then output shaft 21 rotations, cutting knife 3 rotation.Thus, slide being cut on the material, can be cut material by cutting knife 3 cuttings by making base 4.

In addition, be accompanied by the rotation of output shaft 21, as mentioned above, from

air entry

26,26 ... suck tempering air and make it by coming cooling motor 20 in the electric machine casing 5, and in the air entry 27 that is formed with closure part 27, tempering air can enter in the electric machine casing 5 via the opening portion in the outside of closure part 27, also can be tilted the direction of face 28 guiding away from commutator 25, therefore as shown by arrows through the outside of commutator 25 and mobile electric machine casing 5 in.Tempering air does not almost flow directly into the sliding-contact part of commutator 25 and carbon brush 24 thus, so even suck the dust that is produced by cutting with tempering air, can suppress dust yet and invade this sliding-contact part.

Like this, cropper 1 according to aforesaid way, on the inflow direction by the tempering air in air entry 26, the zone of the upstream side of the sliding-contact part of commutator 25 and carbon brush 24 is provided with the closure part 27 that stops tempering air to flow into from this zone, can suppress dust effectively and invade the sliding-contact part of commutator 25 and carbon brush 24, can keep best rectified action and brush life.In addition, because closure part 27 is arranged on necessary minimal zone, so also can avoid the reduction of the cooling effectiveness of motor 20.

In addition, carry out cutting test with the cropper 1 of the closure part 27 that is provided with aforesaid way and cropper that closure part 27 is not set to being cut material, relatively the life-span of carbon brush 24, then can confirm under the situation that is provided with closure part 27, grow about 2 one-tenth life-span than situation about not being provided with.

On the other hand, in aforesaid way, because closure part 27 and electric machine casing 5 are formed, so can form closure part 27 simply.

In addition, 27 tempering air is by the end face of side in the closure part, is formed with tempering air to the inclined plane 28 away from the direction guiding of the sliding-contact part of commutator 25 and carbon brush 24, can suppress dust thus effectively and invade this sliding-contact part.

In addition, as long as the closure part can stop tempering air directly to invade the sliding-contact part of commutator and brush, just can suitably change size and shape according to the inflow direction of tempering air.

In addition, also can change the angle on inclined plane, even yet not influence of inclined plane is not set according to the size of closure part.

And then, also can not as above-mentioned mode, closure part and electric machine casing to be formed, but utilize engaging between fastener or screw in conjunction with etc. seating means will be with the global shape of closure part suitable plugging part as split be installed in the back of electric machine casing, also can form the closure part thus.If adopt such plugging part, then can tackle the existing cutting machine that does not have the closure part simply.

In addition, be not limited to cropper, even other machine such as circular saw also can adopt the present invention as cutting machine.

Claims

1. cutting machine, it is provided with the cutting knife that the driving with described motor is rotated in the place ahead of the housing that contains motor, on the other hand, the brush of back quadrate part setting in described housing and the commutator sliding-contact that on the output shaft of described motor, is provided with, be formed with the air entry of the tempering air of described motor in the back of described housing, it is characterized in that:

Zone at the upstream side of sliding-contact part described air entry, be positioned at described commutator and brush along the inflow direction of described tempering air is provided with the closure part that stops described tempering air to flow into from this zone.

2. cutting machine as claimed in claim 1 is characterized in that:

Described closure part and described housing are integrally formed.

3. cutting machine as claimed in claim 1 or 2 is characterized in that:

Described closure part is at the end face of described tempering air by side, is formed with described tempering air to the inclined plane away from the direction guiding of the sliding-contact part of described commutator and brush.