EP1433569B1

EP1433569B1 - Barrel-polishing apparatus

Info

Publication number: EP1433569B1
Application number: EP04006729A
Authority: EP
Inventors: Shuji Kawasaki
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-12-10
Filing date: 1998-12-02
Publication date: 2006-09-13
Anticipated expiration: 2018-12-02
Also published as: EP1433569A3; DE69829452T2; CA2255501A1; EP1433569A2; DE69835909T2; DE69835909D1; DE69829452D1; KR100312640B1; CA2255501C; KR19990062888A

Description

[FIELD OF THE INVENTION]

This invention relates to a barrel-polishing apparatus.

[PRIOR ART]

From GB 1 540 517 there is known a barrel-polishing apparatus comprising a polishing medium bath with polishing mediums received therein, a base, a slide plate mounted on said base such that said slide plate is reciprocally moved in a direction of said polishing medium bath by reciprocal means, an electrically-operated rotational drive means mounted on said slide plate, a rotary shaft mounted on said electrically-operated rotational drive means and extending in a direction of reciprocal movement of said slide plate, and a workpiece attachment device mounted on a distal end portion of said rotary shaft and adapted to attach a workpiece to said rotary shaft.
If a workpiece is polished while rotating the workpiece in polishing mediums, the polishing mediums are worn. Therefore, in the conventional apparatus, when the aggregate of polishing mediums has been partly worn, the workpiece is moved in the polishing medium bath in an effort to find a non-worn part of the polishing mediums and dipped in the non-worn part of the polishing mediums. By keep doing so in the polishing operation, a certain polishing effect can be obtained.
However, in such a conventional polishing apparatus, since the partial wear of the aggregate of polishing mediums is determined based on the perception or experience of the operator, much labor is required. In addition, since the result of determination is different depending on each operator, a constant polishing effect is difficult to be obtained in an efficient manner.

[OBJECTS OF THE INVENTION]

It is the object of the present invention to provide, in order to obviate the shortcomings inherent in the prior art, a barrel-polishing apparatus, wherein a constant polishing effect can normally be obtained efficiently and automatically even in case an aggregate of the polishing mediums is partly worn (hereinafter referred to "this invention").

[CONSTRUCTION OF THE INVENTION AND OPERATION AND EFFECTS THEREOF]

A barrel-polishing apparatus according to this invention so as to achieve the above object comprises the features stated in claim 1.
Accordingly, when the rotary torque of the workpiece in the polishing mediums is reduced to reduce the electric current supplied to the electrically-operated rotational drive means, the workpiece can be moved in the polishing mediums in such a manner as to increase the rotary torque. On the other hand, when the rotary torque of the workpiece in the polishing mediums is increased to increase the electric current supplied to the electrically-operated rotational drive means, the workpiece can be moved in the polishing mediums in such a manner as to reduce the rotary torque. Therefore, with use of this barrel-polishing apparatus, a constant rotary torque can normally be obtained even if the aggregate of polishing mediums is partly worn. Thus, a constant polishing effect can be obtained efficiently and automatically.
If the slide plate is moved towards the polishing medium bath when the electric current supplied to the electrically-operated rotational drive means is smaller than a reference electric current and the slide plate is moved away from the polishing medium bath when the electric current supplied to the electrically-operated rotational drive means is larger than the reference electric current, the workpiece can easily be moved in the less-worn polishing mediums when the rotary torque is reduced and the workpiece can easily be moved in the more-worn polishing mediums when the rotary torque is increased.
Also, if the base is slanted downwardly towards the polishing medium bath, the workpiece can easily be moved reciprocally with respect to the polishing medium bath.

[BRIEF DESCRIPTION OF THE DRAWINGS]

Fig. 1 is a sectional view of a barrel-polishing apparatus, showing an embodiment of this invention.

[EMBODIMENTS]

In Fig. 1 reference character B denotes a barrel-polishing apparatus. This barrel-polishing apparatus B includes a cylindrical polishing medium bath 20. Reference numerals 21, 21, ... denote polishing mediums which are received in the polishing medium bath 20. Any mediums such as ceramic particles which are usually used, can be used as the polishing mediums 21, 21, ... The polishing method may be a wet polishing or a dry polishing.
Reference numeral 22 denotes an upper end opening of the polishing medium bath 20. Through this upper end opening 22, a workpiece (vehicle wheel made of aluminum in this embodiment) W is dipped in the polishing mediums 21, 21, ...
On the other hand, reference numeral 11 denotes a support bed of the barrel-polishing apparatus B and reference numeral 40 denotes a base swingably mounted on this support bed 11. This base 40 is slanted downwardly in a direction of the polishing medium bath 20. This slanting angle can appropriately be adjusted. The base 40 can stop at an appropriate angle. Reference numeral 52 denotes a geared engine mounted on the base 40, and reference numeral 511 denotes a bolt member connected to the geared engine 52. This bolt member 511 is rotatably supported by one pair of bearings 80, 80 such that it can rotate normally and backwardly about its axis in accordance with rotation of the geared engine 52. This bolt member 51 is disposed along the slanted direction of the base 40. Reference numerals 81, 81 denote guide members.
Reference numeral 50 denotes a slide plate, and reference numerals 512, 512 denote nut members projecting from a lower surface of this slide plate 50. The nut members 512, 512 of the slide plate 50 are threadingly engaged with the bolt member 511 of the base 40. Owing to this arrangement, the slide plate 50 can reciprocally slide in accordance with rotation of the bolt member 511. The bolt member 511, the nut member 512 and the geared engine 52 correspond to the "reciprocal means" of this invention.
The workpiece (aluminum vehicle wheel) W is attached to a distal end of the rotary shaft 60 through a work attachment device (an air chuck) 87 and dipped in the polishing mediums 21, 21, ... of the polishing medium bath 20. Then, the rotational drive portion 61 is actuated to rotate the rotary shaft 60 and thus the workpiece W in the polishing mediums 21, 21, ...
Reference numeral 61 denotes a rotational drive portion (this rotational drive portion corresponds to the "electrically-operated rotary means" of this invention). The rotational drive portion 61 is mounted on the slide plate 50. The rotational drive portion 61 comprises an engine (AC or DC engine) and a reduction gear unit. The rotational drive portion 61 can provide a circular motion through the rotary shaft 60. The rotary shaft 60 extends along the axis of the bolt member 511, i.e., in the slanting direction of the base 40.
The engine (AC or DC) of the rotational drive portion 61 is driven by a power source 92. At that time, the electric current supplied to the engine is measured by a current detector means 93. The result of measurement thus obtained is sent to a control unit 94 where the result of measurement is compared with a preset value (this preset value corresponds to the "reference electric current" of this invention) and then used as a base for control the operation of the geared engine 52.
The polishing mediums 21, 21, ... of the polishing medium bath 20 are, in general, less worn towards the lower layer thereof and more worn towards the upper layer because of frequency of use.
The preset value of the control portion 94 is preliminarily established as a current value to be supplied to the engine in relation to a rotary torque required by the engine of the rotational drive portion 60 in consideration of the size of the workpiece W as an object to be polished, configuration of the workpiece W, a required degree of polishing, etc. This preset value is determined based on experience.
Operation of this apparatus will now be described.
First, the preset value is determined in the control portion 94 based on the size, the configuration, etc. of the workpiece W.
In that condition, the power source for the engine of the rotational drive portion 61 is turned on in the state that the workpiece W is dipped in the polishing mediums 21, 21, ... of the polishing medium bath 20. Then, the rotational drive portion 61 is actuated and the workpiece W is polished in the polishing mediums 21, 21, ... At that time, the electric current supplied to the engine of the rotational dove portion 61 is measured by the electric current detector means 93. Then, the result of measurement thus obtained is sent to the control unit 94 where the result of measurement is compared with the preset value. When the result of measurement is larger than th preset value, i.e., when the rotary torque is large, the geared engine 52 is actuated to rotate the bolt portion 511, so that the slide plate 50 and thus the rotational drive portion 61 is retracted to bring the workpiece W to an upper layer portion of the polishing mediums 21, 21, ...and stop it at a position where the value of measurement of the electric current is equal to the preset value. On the other hand, when the value of measurement is smaller than the preset value, i.e., when the rotary torque is small, the geared engine 52 is actuated to rotate the bolt member 511 backwardly to move the slide plate 50 and thus, the rotational drive portion 61 forwardly, so that the workpiece W is brought to a lower layer portion of the polishing mediums 21, 21, ... and stop it at a position where the value of measurement of the electric current is equal to the preset value.

Claims

A barrel-polishing apparatus (B) comprising a polishing medium bath (20) with polishing mediums (21) received therein, a base (40), a slide plate (50) mounted on said base (40) such that said slide plate (50) is reciprocally moved in a direction of said polishing medium bath (20) by reciprocal means (52, 511, 512), an electrically-operated rotational drive means (61) mounted on said slide plate (50), a rotary shaft (60) mounted on said electrically-operated rotational drive means (61) and extending in a direction of reciprocal movement of said slide plate (50), and a workpiece attachment device (87) mounted on a distal end portion of said rotary shaft (60) and adapted to attach a workpiece (W) to said rotary shaft (60), characterized in that said barrel-polishing apparatus (B) further comprises a control unit (94) for controlling a reciprocal movement of said reciprocal means (52, 511, 512) by detecting an electric current supplied to said electrically-operated rotational drive means (61).
A barrel-polishing apparatus (B) according to claim 1, characterized in that said slide plate (50) is moved towards said polishing medium bath (20) when the electric current supplied to said electrically-operated rotational drive means (61) is smaller than a reference electric current and said slide plate (50) is moved away from said polishing medium bath (20) when the electric current supplied to said electrically-operated rotational drive means (61) is larger than said reference electric current.
A barrel-polishing apparatus (B) according to claim 1 or 2, characterized in that said base (40) is slanted downwardly towards said polishing medium bath (20).