GB2514575A

GB2514575A - Scribing method and scribing apparatus

Info

Publication number: GB2514575A
Application number: GB1309567.4A
Authority: GB
Inventors: Marc Irvine; Aubrey Roff; Shunsuke Ishii
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2013-05-29
Filing date: 2013-05-29
Publication date: 2014-12-03
Anticipated expiration: 2033-05-29
Also published as: GB2514575B; GB201309567D0

Abstract

A scribing method includes the steps of placing a rest 18 with a slot (19, fig. 1) such that the slot faces toward a surface of a workpiece W, which is disposed opposite to a to-be-machined surface S of the workpiece, and forming a notch 24 in the workpiece with a stylus 14 while the workpiece is borne by the rest. The notch is preferably at least 0.2 mm deep. The method may also comprise ejecting a gas toward a tip 22 of the stylus during each cycle of forming the notch. A scribing apparatus 10 includes a stylus 14 for forming a notch 24 in a to-be-machined surface S of a workpiece W, and a rest 18 for bearing a surface of the workpiece, which is disposed opposite to the to-be-machined surface thereof. The notch is formed in the to-be-machined surface of the workpiece by the stylus while the slot (19) faces toward the surface of the workpiece, which is disposed opposite to the to-be-machined surface. The slot is preferably between 0.1 and 0.2 mm deep. The apparatus may further comprise a blower mechanism 32 for ejecting a gas toward a tip 22 of the stylus.

Description

SCRIBING METHOD AND SCRIBING APPARATUS

BACKGROUND OF THE INVENTION

Field of the Invention:

The present invention relates to a method of and an apparatus for scribing letters, marks, etc.1 on the surface of a workpiece by scoring notches therein.

Description of the Related Art;

Heretofore, automatized factories for producing automobiles, construction machines, etc., have used automatic marking apparatus for scoring identifiers such as lot numbers, serial numbers, or the like made up of letters, marks, etc., in workpieces. Such automatic marking apparatus are classified into stamping apparatus, which use a press to press a stamp against a workpiece to form imprints thereon, and scribing apparatus, which use a stylus to form notches in a workpiece to score letters, marks, etc., thereon. One conventional automatic marking apparatus in the form of a scribing apparatus is disclosed in Japanese Laid-Open Patent Publication No. 2009-125817, for example.

Stamping apparatus are disadvantageous in that they require large-scale equipment to be actualized, are costly since they use different dedicated stamps for imprinting different identifiers, cause a loss of time when the stamps are replaced, and require a storage space for storing the stamps.

Scribing apparatus do not cause a loss of time due to stamp replacement, or require a stamp storage space because such scribing apparatus do not use different dedicated stamps for imprinting different types of identifiers.

SUMMARY OF THE INVENTION

when a scribing apparatus is used to score letters, marks, etc., on a workpiece, it is preferable to scribe such identifiers clearly so that the identifiers will be accurately recognized on the workpiece. In particular, if letters, marks, etc., that are scribed on a workpiece are to be recognized by an automatic recognition system using a camera, then the letters, marks, etc., preferably are scored on the workpiece by forming notches having at least a certain depth of 0.2 mm, for example, in the workpiece, so that the automatic recognition system will be able to accurately recognize the scribed letters, marks, etc. It is an object of the present invention to provide a method of and an apparatus for scribing letters, marks, etc., on the surface of a workpiece by scoring notches in the surface to at least a prescribed depth.

To achieve the above object, there is provided in accordance with the present invention a scribing method of scoring a notch in a workpiece with a stylus, comprising the steps of placing a workpiece rest with a slot defined therein so that the slot faces toward a surface of the workpiece, which is disposed opposite to a to-be-machined surface of the worlcpiece, and forming the notch in the workpiece with the stylus while the workpiece is borne by the woripiece rest.

With the above scribing method, inasmuch as the workpiece rest that bears the workpiece thereon has the slot, when the stylus forms the notch in the workpiece, the surface of the workplace, which is disposed opposite to the to-be-machined surface and which faces toward the slot, is plastically deformed into the slot. Therefore, the stylus can scrape the workpiece more deeply than if the workpiece rest were free of the slot, and hence the stylus can form a notch, the depth of which is equal to or greater than a prescribed depth. Consequently, it is possible to score clearer letters or the like in the to-be-machined surface of the workplace.

In the scribing method, the notch may have a depth of at least D.2 mm. Consequently, letters or the like, which are scored in the workpiece, can easily be recognized by an automatic recognition system using a camera.

In the scribing method, a gas may be applied to a tip of the stylus during each cycle of forming the notch. When gas is applied to the tip of the stylus, chips scraped off the workpiece and deposited on the tip of the stylus are blown away by the gas. Accordingly, the tip of the stylus can accurately be measured for an amount of wear, which is caused during each cycle of forming a notch, In addition, since a next notch is formed in the workpiece after chips deposited on the tip of the stylus have been removed by the gas, the width of the notch is not adversely affected by the chips, and hence the width of the notch can easily be managed.

According to the present invention, there also is provided a scribing apparatus comprising a stylus f or forming a notch in a to-be-machined surface of a workpiece, and a workpiece rest with a slot defined therein for bearing a surface of the workpiece, which is disposed opposite to the to-be-machined surface, wherein the notch is formed in the to-be-machined surface of the workpiece by the stylus while the slot faces toward the surface of the workpiece, which is disposed opposite to the to-be-machined surface.

With the above arrangement of the scribing apparatus, the stylus can scrape the workpiece more deeply than if the workpiece rest did not include the slot, and hence the scribing apparatus can form a notch, the depth of which is equal to or greater than a prescribed depth. Consequently, it is possible to score clearer letters or the like in the to-be-machined surface of the workpiece.

In the scribing apparatus, the slot has a depth ranging from 0.1 to 0.2 mm. The notch, which has a depth equal to or greater than a prescribed depth, can easily be formed in the workpiece. Also, regions of the workpiece around the notch are effectively prevented from becoming plastically deformed significantly, Consequently, letters, marks, etc., can clearly be scored in the workpiece.

In the scribing apparatus, the workpiece rest may comprise a member having longitudinal and transverse directions, wherein the slot extends in the longitudinal direction. Therefore, the workpiece rest allows identifiers including a straight array of letters or the like to be clearly scored in the workpiece.

The scribing apparatus may further comprise a blower mechanism for ejecting a gas toward a tip of the stylus. When gas is applied to the tip of the stylus, chips scraped off the workpiece and deposited on the tip of the stylus are blown away by the gas. Accordingly, the tip of the stylus can accurately be measured for an amount of wear caused during each cycle of forming a notch. In addition, since a next notch is formed in the workpiece after chips deposited on the tip of the stylus have been removed by the gas, the width of the notch is not adversely affected by the chips, and hence the width of the notch can easily be managed.

The scribing method and the scribing apparatus according to the present invention make it easy to form a notch having a prescribed depth or greater in a to-be-machined surface of a workpiece.

The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a scribing apparatus according to an embodiment of the present invention; FIG. 2 is a fragmentary transverse cross-sectional view of a workpiece rest of the scribing apparatus shown in FIG. 1; FIG. 3A is a fragmentary transverse cross-sectional view of the workpiece rest with a workpiece placed thereon by a scribing method according to an embodiment of the present invention; FIG. 33 is a fragmentary transverse cross-sectional view of the workpiece rest with a notch formed in the workpiece by the scribing method according to the embodiment of the present invention; FIG. 4 is a fragmentary transverse cross-sectional view of a workpiece rest with a notch formed in a workpiece by a scribing method according to a comparative example; and -FIG. S is a fragmentary side elevational view of a blower mechanism incorporated in the scribing apparatus shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A scribing method and a scribing apparatus according to a preferred embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows in perspective a scribing apparatus 10 H according to an embodiment of the present invention. As shown in FIG. 1, the scribing apparatus 10 forms a notch 24 (see FIG. 33) on the surface (to-be--machined surface 5) of a workpiece W in order to draw or score letters, numerals, symbols, figures, marks, etc., (hereinafter referred to as "letters or the like'T) on the workpiece W. The scribing apparatus 10 is able to carry out a scribing method according to the embodiment of the P present invention.

The scribing apparatus 10 includes a main frame 12, a stylus 14, a displacing mechanism 16, and a workpiece rest 18. The main frame 12 is mounted on an end eftector of a robot such as an articulated robot, for example. The robot is capable of changing the position of the end effector in a three-dimensional space. when letters or the like are formed on the workpiece W by the scribing apparatus 10, the scribing apparatus 10 is positioned by the robot with respect to the workpiece W. The main frame 12 may be installed in a fixed position rather than being mounted on a robot.

The stylus 14 is a tool for scoring the notch 24 in the workpiece W. The workpiece W, which is machined by the scribing apparatus 10, may be a component of an automobile, a construction machine, or the like. In the case of a component of an automobile, the component may be a panel of an automobile body, such as a floor panel, a side panel, or the like, for example. The wor]cpiece W machined by the scribing method and the scribing apparatus 10 according to the embodiment of the present invention typically is a plate-like member.

The stylus 14 has a stylus body 20, and a tip 22 mounted on a distal end of the stylus body 20. The tip 22 is of a tapered shape and is made of a hard material, which is hard enough to scrape the to-be-machined surface S of the workpiece W and form the notch 24 therein. The hard material of the tip 22 may be cemented carbide, diamond, or the like, for example.

The stylus 14 need not necessarily be made up of the stylus body 20 and the tip 22 combined together, but may be a single component made of a hard material such as cemented carbide or the like.

The stylus 14 can be moved three-dimensionally by the displacing mechanism 16. The displacing mechanism 16 is capable of displacing the stylus 14 along X and Y directions perpendicular to the longitudinal axis of the stylus 14, as well as along a Z direction parallel to the longitudinal axis of the stylus 14. Although not shown in detail in FIG. 1, the displacing mechanism 16 H includes respective mechanisms for displacing the stylus 14 along the X, Y, and Z directions.

The scribing apparatus 10 also includes an abutment plate 26 disposed beneath the displacing mechanism 16 and laterally of the stylus 14. The abutment plate 26 abuts against the workpiece W so as to position the workpiece W on the workpiece rest 18 when the stylus 14 forms the notch 24 in the workpiece W. The workpiece rest 18 is disposed in a position confronting the stylus 14, i.e., in a position below the stylus 14 as shown in FIG. 1. The wor)cpiece rest 18 is fixedly supported on the main frame 12. The workpiece rest 18 bears or supports a surface (reverse side) of the workpiece W, which is opposite to the to-be-machined surface S thereof, The workpiece rest 18 is made of a hard material, which is hard enough to prevent the workpiece rest 18 from becoming deformed when the stylus 14 forms the notch 24 in the workpiece w on the workpiece rest 18. The hard material of the workpiece rest 18 may be any of various alloys such as stainless steel, aluminum alloy, or the like, for example.

According to the illustrated embodiment, the workpiece rest 18 comprises a member having a rectangular shape with longitudinal and transverse directions as viewed in plan. The longitudinal direction of the workpiece rest 18 extends in the X direction. The workpiece rest 18 has a surface l8a that faces toward the stylus 14, i.e., a surface bearing the workpiece w thereon, the surface 18a including a slot 19 defined therein, which extends along the longitudinal direction of the workpiece rest 18, i.e., in the X direction.

The slot 19 has a width, i.e., a dimension in the Y direction in FIG. 1. The width of the slot 19 may be constant or may vary along the direction in which the slot 19 extends, i.e., along the X direction. The slot 19 has opposite ends, which reach and open at opposite ends of the workpiece rest 18 along the longitudinal direction+ Alternatively, the opposite ends of the slot 19 may terminate short of and be closed at opposite ends of the workpiece rest 18 along the longitudinal direction.

FIG. 2 is a transverse cross-sectional view of the workpiece rest 18. As shown in FIG. 2, the slot 19 is in the shape of a groove having a small depth U, which may be within a range from about 0.1 to 0.2 mm. If the depth U is too small, i.e., smaller than the above ranger then it is difficult for the notch 24 (FIG. 3B) to have a desired depth when the notch 24 is formed in the workpiece W. If the depth D is too large, i.e., larger than the above ranger then regions of the workpiece W around the notch 24 may become plastically deformed significantly when the stylus 14 is pressed against the workpiece w to form the notch 24 therein.

The scribing apparatus 10 according to the present embodiment is basically constructed as described above.

operations and advantages of the scribing apparatus 10 will be described below in combination with the scribing method.

For scoring letters or the like in the to-be-machined surface S of the workpiece W, the scribing apparatus 10 is positioned by the robot with respect to the workpiece W. At this time, as shown in FIG. 3A, the workpiece rest 18 is positioned such that the slot 19 faces toward the reverse side of the workpiece W, which is opposite to the to-be-machined surface S, so that the workpiece rest 18 bears the workpiece W thereon (placing step).

Then, while the stylus 14, i.e., the tip22 of the stylus 14, is pressed against the to-be-machined surface S of the workpiece W, the stylus 14 is moved along the plane of the to-be-machined surface S. thereby scraping the workpiece W with the tip 22 of the stylus 14. In this manner, as shown in FIG. 3B, the notch 24, which has a V-shape in cross section, is formed in the workpiece W while the workpiece W is borne by the workpiece rest 18 (notch forming step) . At this time, the stylus 14 may be vibrated axially along the Z direction while being pressed against the workpiece W. When the notch 24 is formed in the worlcpiece W, convex burrs 25 are formed on edges of the notch 24 at the opening thereof. As the notch 24 is formed, a ridge 28 also is formed on the reverse side of the workpiece W and projects into the slot 19 of the workpiece rest 18.

The ridge 28 is positioned in alignment with the bottom of the notch 24, i.e., the lower crest of the v-shaped cross section of the notch 24.

The above process of forming the notch 24 by scraping the workpiece W with the stylus 14 is repeated as many times as the nuniber of required cycles, thereby forming a plurality of desired letters or the like on the workpiece W. Actually, one or more letters or the like may be formed on the workpiece W. FIG. 4 is a fragmentary transverse cross-sectional view of a workpiece rest 30 with a workpiece Vi thereon1 which is notched by a scribing method according to a comparative example. The workpiece rest 30, which is used in the scribing method according to the comparative example, has a flat surface 30a that bears the workpiece w thereon, the flat surface 30a being free of the slot 19. It has been confirmed by the inventor of the present invention that when the workpiece VI is supported on the workpiece rest 30 and a notch 24a is formed in the workpiece W by a stylus, it is difficult for the notch 24a to be formed having a depth P2 (i+e+, the distance from the to-be-machined surface S of the workpiece VI to the crest of the V-shaped cross section of the notch 24a) that is eua1 to or greater than a desired depth of 0.2 mm, for example.

when the notch 24 is formed in the workpiece W by the scribing method and the scribing apparatus 10 according to the present embodiment, the reverse side of the workpiece becomes raised as the notch 24 is formed, as shown in FIG. 33, thereby producing the ridge 28 that projects into the slot 19 formed in the workpiece rest 18. At this time, according to the present embodiment, since the ridge 28 of the workpiece W abuts against a bottom 19a of the slot 19, regions of the workpiece W around the notch 24 are not plastically deformed significantly.

The notch 24 thus formed has a depth Dl, which is greater than the depth D2 of the notch 24a shown in FIG. 4, i.e.1 the notch 24a formed by the scribing method according to the comparative example. This is because when the notch 24 is formed in the workpiece W with the slot 19 being positioned to face the reverse side of the workpiece W, which is opposite to the to-be-machined surface B, the reverse side of the workpiece W is deformed, i.e., raised, into the Blot 191 thereby making it easier to form the notch 24 in the workpiece W. With the scribing method and the scribing apparatus 10 according to the present embodiment, inasmuch as the workpiece rest 18 that bears the workpiece W has the slot 19, when the stylus 14 forms the notch 24 in the workpiece W. the reverse side of the workpiece W, which is opposite to the to-be-machined surface S and faces toward the slot 19, is plastically deformed into the slot 19. Therefore, the stylus 14 can scrape the workpiece W more deeply than if the workpiece rest 30 were free of the slot 19 (see FIG. 4), and hence, the stylus 14 can form a notch 24 having a depth that is equal to or greater than a prescribed depth of 0.2 mm.

Consequently, it is possible to score clearer letters or the like in the to-be--machined surface S of the workpiece W. The letters or the like, which are made up of notches 24 having a depth of 0.2 trim or greater, can easily be recognized by an automatic recognition system using a camera.

If the depth D of the slot 19 is in the range from about 0_i to 0.2 mm, then the notch 24, a depth of which is 0.2 mm or greater, can easily be formed in the workpiece w, and regions of the workpiece W around the notch 24 are effectively prevented from becoming plastically deformed significantly. Consequently, letters, marks, etc., can clearly be scored in the workpiece W, and can easily be recognized by an automatic recognition system using a camera.

According to the present embodiment, as shown in FIG. 1, the workpiece rest 18 comprises a member with a rectangular shape having longitudinal and transverse directions, and the slot 19 extends in the longitudinal direction. Therefore, the workpiece rest 18 allows identifiers including a straight array of letters or the like to be scored clearly in the workpiece W. As shown in FIG. 5, the scribing apparatus 10 may additionally include a blower mechanism 32 for ejecting a gas 0 to the tip 22 of the stylus 14. The blower mechanism 32 includes a nozzle 34 directed toward the tip 22 of the stylus 14, a gas line 36 one end of which is connected to the nozzle 34, and a gas supply source 38 such as a pump or the like connected to the other end 6 of the gas line 36.

The nozzle 34 is mounted on a stay or bracket 35 which is fixed to the stylus body 20. The gas G, which is ejected from the nozzle 34, may be air, nitrogen, or the like. The gas line 36 includes an on-off valve, not shown, for supplying gas or stopping supply of gas G to the nozzle 34 from the gas supply source 38 through the gas line 36. The on-off valve is controlled by a non-illustrated controller.

In the blower mechanism 32, after the stylus 14 has foed a notch 24 in the workpiece W and before the stylus 14 forms a next notch 24 in the workpiece W, the stylus 14 is spaced from the workpiece W, as shown in FIG. 5. While the stylus 14 is spaced from the workpiece W, the blower mechanism 32 ejects gas to the tip 22 of the stylus 14. In other words, the blower mechanism 32 ejects gas to the tip 22 of the stylus 14 during each cycle of forming a notch 24.

when the blower mechanism 32 ejects gas to the tip 22 of the stylus 14, chips that are scraped of f the workpiece W and deposited on the tip 22 of the stylus 14 are blown away by the gas. Accordingly, the tip 22 of the stylus 14 can accurately be measured for an amount of wear caused during each cycle of forming a notch 24.

In addition, since a next notch 24 is formed in the workpiece W after the chips, which are deposited on the tip 22 of the stylus 14, have been removed by the blower mechanism 32. the width of the notch 24 is not adversely affected by the chips, and hence the width of the notch 24 can easily be managed.

Claims

CLAIMS1. A scribing method of scoring a notch in a workpiece with a stylus, comprising the steps of: placing a workpiece rest with a slot defined therein so that the slot faces toward a surface of the woriece, which is disposed opposite to a to-be-machined surface of the workpiece; and forming the notch in the woricpiece with the stylus while the workpiece is borne by the wor]piece rest.
2. The scribing method according to claim 1, wherein the notch has a depth of at least 0.2 mm.
3. The scribing method according to claim 1 or 2, further comprising: ejecting a gas toward a tip of the stylus during each cycle of forming the notch.
4. A scribing apparatus comprising: a stylus for forming a notch in a to-be-machined surface of a workpiece; and a workpiece rest with a slot defined therein for bearing a surface of the workpiece, which is disposed opposite to the to-be-machined surface; wherein the notch is formed in the to-be-machined surface of the workpiece by the stylus while the slot faces toward the surface of the workpiece, which is disposed opposite to the to-be-machined surface.
5. The scribing apparatus according to claim 4, wherein the slot has a depth ranging from 0.1 to 0.2 mm.
6. The scribing apparatus according to claim 4 or 5, wherein the workpiece rest comprises a member having longitudinal and transverse directions, the slot extending in the longitudinal direction.
7. The scribing apparatus according to any one of claims 4 through 6, further comprising: a blower mechanism for ejecting a gas toward a tip of the stylus.