JP3925141B2 - Work positioning method and work positioning device for machine tool - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a machine tool represented by a machining center. Work positioning method and With regard to workpiece positioning devices, especially when machining multiple types of workpieces with different specifications on the same machine tool, workpieces of each specification are shared by using different jigs for each specification by manual changeover. The positioning clamp was made to Work positioning method and The present invention relates to a workpiece positioning device.
[0002]
[Prior art and problems to be solved by the invention]
When machining multiple-spec workpieces with slightly different detailed structures, such as a cylinder head of an automobile engine, with a common machine tool such as a machining center, Therefore, since the positioning reference position and the clamping position are slightly different, it is effective to position and fix the workpiece on the workpiece base using a positioning jig set for each specification in advance. In particular, when a machine tool having a high degree of machining freedom such as a machining center and a work base having an indexing function by tilt rotation are used in combination, the tendency becomes more remarkable.
[0003]
However, since the positioning jig must have at least the locate function, the clamp function, and the lift function, the entire jig must be complicated and large. The preparation not only causes a significant increase in equipment cost but also requires a jig changing device, which is not preferable. In particular, when it is assumed that the workpiece is set manually by the operator, it is desirable that the positioning jig to be replaced for each workpiece specification is also easy for the operator to handle.
[0004]
The present invention was made paying attention to such a problem, especially while assuming that the workpiece is carried in and out and the jig change for each specification (setup change) is performed manually by the operator, While the workpiece clamping function can be used in common with workpieces of all specifications, the jig to be replaced for each workpiece specification is extremely simple so that the operator can easily handle it. Possible and did Work positioning method and work positioning The device is to be provided.
[0005]
[Means for Solving the Problems]
According to the first aspect of the present invention, when any one of a plurality of types of workpieces having different specifications is clamped to a workpiece base and machined by a common machine tool, the positioning reference portion for the workpiece base is a workpiece. A cassette jig of a specific specification that is standardized regardless of the difference in specifications and set so that the positioning reference part for the workpiece differs for each workpiece specification is detachably positioned and fixed to the workpiece base. A workpiece with the corresponding specifications is positioned using this cassette jig as a reference, and a drift jig is attached to the workpiece so that it can be used in common regardless of differences in the specifications of the workpiece. The workpiece is clamped to the workpiece base using the clamping mechanism provided on the workpiece base. To do It is characterized by.
[0006]
Therefore, in the first aspect of the invention, the workpiece is positioned relative to the workpiece base by using the cassette jig set for each workpiece specification, and at the same time, the difference in workpiece specifications is achieved by using the drift jig together. Regardless of the workpiece, the workpiece is clamped to the workpiece base with a common clamping mechanism. This eliminates the need to attach a clamp mechanism to the cassette jig for each specification.
[0007]
The invention described in claim 2 is described in claim 1. The workpiece positioning device used in the workpiece positioning method As a premise, a workpiece conveying conveyor is disposed adjacent to the workpiece base, and the workpiece base is provided with a workpiece lifter for raising and lowering the workpiece relative to the cassette jig. The work lifter is supported by an elevating drive means such as a lift cylinder provided on the work base side, and is supported by the elevating drive means so that it can be raised and lowered below the work in the cassette jig. A workpiece rail extending toward the conveyor to function as a workpiece feeding path when the workpiece is carried in and out of the workpiece base and the conveyor, and the workpiece rail is raised Is characterized in that the height position is set to be the same height as the conveyor level of the conveyor.
[0008]
Therefore, according to the second aspect of the present invention, at the time of loading / unloading the workpiece between the workpiece base and the workpiece conveying conveyor, the workpiece lifter is driven upward so that at least the conveyor conveyance level and the workpiece rail are set. And the same height position. For example, when a workpiece is loaded, the worker carries the workpiece on the conveyor onto the cassette jig so as to slide on the workpiece rail, and if the workpiece lifter is lowered in this state, the workpiece is moved to the workpiece rail. At the same time, it is lowered by a predetermined amount and positioned autonomously with respect to the cassette jig. In addition, when the workpiece is unloaded, the procedure is opposite to the above procedure.
[0009]
According to the third aspect of the present invention, on the premise of the second aspect, the work base is configured to push up the cassette jig on the work base to the same height position as the conveyor conveyance level when replacing the cassette jig. A feature lifter is provided.
[0010]
Here, as in the case of loading / unloading of workpieces between the workpiece base and the conveyor, it functions as a cassette jig feeding path in preparation for loading / unloading of the cassette jig between the workpiece base and the conveyor. It is desirable to provide a rail on the work base side.
[0011]
Therefore, in the invention according to the third aspect, the cassette jig is easily carried in and out between the work base and the conveyor in the same manner as in the case of carrying in and out the work.
[0012]
According to a fourth aspect of the invention, on the premise of the third aspect of the invention, the work base is supported so that the work base can rotate about a horizontal axis with respect to the jig frame and can be indexed at an arbitrary rotational position. The lifting / lowering driving means of the work lifter and the jig lifter are arranged on the jig frame side.
[0013]
Therefore, in the invention described in claim 4, only the clamp mechanism including an actuator such as a clamp cylinder is attached to the movable work base. The workpiece is securely clamped.
[0014]
【The invention's effect】
According to the first aspect of the present invention, by using the drift jig together with the cassette jig set for each specification, and sharing the clamp part regardless of the difference in workpiece specifications, each cassette jig The clamp mechanism provided on the workpiece base can be used in common for all workpiece clamps, and the structure of the cassette jig for each specification can be simplified. This can contribute to reduction of equipment costs.
[0015]
According to the second aspect of the present invention, the lifting / lowering driving means for the work lifter is provided on the common work base side, while the work rail that is lifted and lowered by the lifting / lowering driving means is guided and supported to the cassette jig side. As a result, the lifting drive means is used in common with the workpieces of each specification, so it is not necessary to attach the lifting drive means to the cassette jig for each specification. In addition to simplification, the work rail functions as a work feeding path, and thus there is an advantage that the work can be carried in and out smoothly between the work base and the conveyor.
[0016]
According to the invention described in claim 3, since the jig lifter that pushes up the cassette jig to the conveyor transport level when the cassette jig is replaced is provided, in addition to the same effect as the invention described in claim 2, There is an advantage that the cassette jig can be easily carried in and out between the work base and the conveyor.
[0017]
According to the fourth aspect of the present invention, since the work base is of the tilt type, only the clamp mechanism is attached to the work base which is a movable part, and therefore many actuators are attached to the movable part. There is an advantage that the structure of the work base can be further simplified.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
1 and the following drawings show a preferred embodiment of the present invention and show a machining process of a cylinder head (hereinafter referred to as a workpiece) by a machining center.
[0019]
As shown in FIGS. 1 to 3, a tilt type work positioning jig 3 is disposed adjacent to a horizontal machining center 1 having an automatic tool change function with respect to the spindle 2, and the work positioning jig A roller conveyor 4 for conveying workpieces is arranged outside the 3. Then, the worker M stands on the step 5 in FIG. 1, and the workpiece W is carried in and out between the roller conveyor 4 and the workpiece positioning jig 3. That is, the workpiece W sent from the previous process using the roller conveyor 4 is set on the workpiece positioning jig 3 and used for machining by the machining center 1, while the workpiece W after machining is transferred from the workpiece positioning jig 3 to the roller. It will be taken out to the conveyor 4 side and sent to the next process.
[0020]
As shown in FIGS. 4 to 6, the workpiece positioning jig 3 is obtained by supporting a workpiece base 8 having a substantially upward U shape on a leg-shaped jig frame 6 via a bracket 7 in a both-side supported state. Thus, it is possible to rotate the tilt drive means 9 mainly composed of a servo motor or the like to an arbitrary position of 360 ° with the horizontal tilt center C as the rotation center, and at the same time, the position is indexed and positioned. Can be done.
[0021]
Here, in the present embodiment, since the work base 8 is commonly used for a plurality of types of work W having different specifications as described later, each work W is not directly positioned on the work base 8. In addition, the workpiece W is positioned on the workpiece base 8 through a cassette jig 10 prepared in advance according to the specifications of each workpiece W. At the same time, when the workpiece W is clamped, in order to cope with the workpiece W of each specification with the common clamper 11, as described later, a drift treatment prepared in advance for each specification of each workpiece W is directly clamped without clamping the workpiece W. It clamps via the tool 21.
[0022]
7 to 9 show details of the work base 8. A state in which only the work base 8 is taken out for easy understanding of the structure is shown in FIGS. As shown in FIGS. 7 to 9 and FIGS. 10 to 12, the work base 8 is provided with a pair of left and right clampers 11 as a clamping mechanism, and a reference sheet surface in which a window 12 is formed in the center. 8a is provided with a plurality of eccentric clamp nuts 14 as well as a plurality of reference blocks 13 which are positioning reference portions for positioning the cassette jig 10 for each workpiece W specification. Note that the rectangular jig plate 15 serving as the base of the cassette jig 10 for each specification is made common in advance regardless of the difference in the specifications of the workpiece W.
[0023]
The clamper 11 has a well-known structure in which the clamp arm 17 is moved toward and away from the reference sheet surface 8a, that is, is clamped and unclamped while the clamp arm 17 is turned about 90 ° in accordance with the expansion and contraction operation of the clamp cylinder 16. The eccentric clamp nut 14 is relatively displaced according to the amount of eccentricity by the rotation operation of the screw on the other side, and the cassette jig 10 is used as the reference block 13 with any flat surface of the hexagon as a contact surface. It is pressed and clamped. Therefore, as will be described later, the cassette jig 10 of any specification is positioned and clamped at the same position on the reference sheet surface 8a using the reference block 13 as a positioning reference portion.
[0024]
13 and 14 show details of a cassette jig having a specific specification. 13 and 14 show a state where only the cassette jig 10 is taken out from FIGS. 7 to 9 in order to facilitate understanding of the structure. As shown in FIGS. 7 to 9 and FIGS. 13 and 14, a window 18 is formed in the central portion of the rectangular jig plate 15 having a common shape regardless of the specification, like the work base 8. At the same time, a plurality of locating pins 20 are fixed to the jig plate 15 in addition to a plurality of seat pads 19 serving as a workpiece seating surface. The seat pad 19 and the locate pin 20 both function as positioning reference portions for the workpiece W to be positioned on the cassette jig 10, and the dimensions L1 to L3 of each portion depend on the specifications of the workpiece W. It is a little different. That is, when the cassette jigs 10 and 10 having different specifications are compared with each other, the arrangement of the seat pad 19 and the locating pin 20 can be individually set according to the specifications of the workpiece W even if the shape of the jig plate 15 serving as a base is common. Will be different. And the workpiece | work W positioned on the cassette jig | tool 10 on the basis of the said seat pad 19 and the locate pin 20 is the drift jig | tool 21 with which the workpiece | work W is previously mounted | worn as shown to FIGS. 7-9 and FIGS. 10-12. Are clamped to the work base 8 together with the cassette jig 10 by the clamper 11. The drift jig 21 will be described later.
[0025]
A pair of left and right work rails 22 are disposed on the jig plate 15 of the cassette jig 10. These work rails 22 extend from the work base 8 side toward the work conveyor roller conveyor 4 side as shown in FIGS. 5 and 6, and between the roller conveyor 4 and the work base 8 as will be described later. When the work W is carried in and out, the work feeding path is functioned. As shown in FIG. 15, each work rail 22 is guided and supported by a holder 23 fixed to the jig plate 15 through a bush 24 and a guide rod 25 so as to be raised and lowered by a predetermined stroke α. In a state where the workpiece W is positioned by the 19 or the locate pin 20, it is set so as not to contact the workpiece W. These work rails 22 form a work lifter 26 together with a lift cylinder 34 and a lifter table 31 as lifting drive means, which will be described later, and lift up by a predetermined stroke α after the completion of processing to locate the locate pin 20 and the work W. The workpiece W can be lifted from the cassette jig 10 while releasing the mutual fitting.
[0026]
The pair of work rails 22 contact and support the bottom surface of the work W. However, as shown in FIGS. 7 to 9, the jig base 15 has a work piece separately from the pair of work rails 22. Another side rail 27 is provided to contact and guide the side surface of W. A pair of left and right jig rails 28 is also formed on the work base 8 side so as to be parallel to the work rails 22, and the jig rails 28 are used to replace the cassette jig 10 as will be described later. Used when
[0027]
Here, the drift jig 21 used in combination with the cassette jig 10 will be described. As shown in FIGS. 9 and 12, the drift jig 21 has a bar pair of left and right locating pin portions 59 and 59 as shown in FIGS. A pair of drift jigs 21 is used for one workpiece W regardless of the difference in specifications of the workpiece W. The drift jig 21 is positioned by fitting a pair of locating pin portions 59 into bolt holes or the like on the workpiece W side as shown in FIG. 16, for example, as shown in FIG. Even if the dimensions L4, L5, etc. of each part are slightly different according to the specifications, the dimension L necessary for clamping has a function of having a constant value regardless of the specifications of the workpiece W. Thus, on the premise that the cassette jig 10 and the drift jig 21 dedicated to each work specification are used, the work W of any specification can be reliably clamped by the common clamper 11. It has become.
[0028]
As shown in FIGS. 7, 8, and 10, a pair of left and right push rods 29 are provided at positions corresponding to the left and right ends of the cassette jig 10 on the reference sheet surface 8 a of the work base 8. Although the push rod 29 is supported so as to be movable up and down with respect to the work base 8, the upper end of the push rod 29 does not protrude beyond the reference sheet surface 8a when the cassette jig 10 is positioned on the reference sheet surface 8a. It is urged downward by the compression coil spring 30.
[0029]
On the other hand, as shown in FIGS. 4 to 6 and FIG. 7, the jig base 6 supporting the work base 8 can be moved up and down through windows 12 and 18 of the work base 8 and each cassette jig 10. A lifter table 31 and a jig lift cylinder 32 are provided as a jig lifter.
[0030]
The lifter table 31 moves up and down in accordance with the expansion and contraction of the lift cylinder 34 while being guided by a pair of left and right guide rods 33, together with the pair of work rails 22 on the cassette jig 10 side described above. A work lifter 26 is formed. Therefore, as shown in FIG. 15, when at least the workpiece W on the cassette jig 10 is in an unclamped state, the lifter table 31 is raised through the work base 8 and the windows 12 and 18 of each cassette jig 10. As a result, the lifter table 31 lifts the workpiece W directly while lifting the pair of left and right workpiece rails 22 by a stroke α.
[0031]
The pair of left and right jig lift cylinders 32 provided on both sides of the lifter table 31 coincide with the position of the push rod 29 on the work base 8 side shown in FIGS. By pushing up the push rod 29 by the lift cylinder 32, the cassette jig 10 is lifted up by a predetermined amount with respect to the reference sheet surface 8 a of the work base 8.
[0032]
Next, a procedure for carrying in / out the workpiece in the equipment configured as described above will be described.
[0033]
First, assuming that a cassette jig 10 having a specific specification is clamped in advance on the work base 8 and the pair of clampers 11 are in an unclamped state, as shown in FIGS. M carries the work W of the corresponding specification sent on the roller conveyor 4 onto the cassette jig 10 manually. At this time, the work base 8 is indexed and stopped so that the reference sheet surface 8a of the work base 8 becomes horizontal, that is, the state shown in FIGS.
[0034]
Prior to the loading of the workpiece W, the worker M sets a pair of drift jigs 21 having specifications corresponding to a predetermined position of the workpiece W as shown in FIGS. At the same time, at this stage, the lifter table 31 forming the work lifter 26 is stopped at the ascending limit position Q1 shown in FIGS. 4 and 7, and as a result, as shown in FIGS. The work rail 22 is lifted up by a predetermined stroke α, and the work rail 22 is at the same height as the transport level of the roller conveyor 4.
[0035]
The worker M pushes the workpiece W on the roller conveyor 4 toward the workpiece base 8 and positions the workpiece W on the cassette jig 10. That is, by pushing the work W along the side rails 27 shown in FIGS. 7 to 9 so as to slide on the pair of work rails 22 functioning as work feeding paths, the work W is smoothly smoothed. The workpiece W is loaded onto the cassette jig 10, and finally the workpiece W is supported by the lifter table 31 and the pair of workpiece rails 22.
[0036]
When the workpiece W having a specific specification is loaded onto the cassette jig 10, the lifter table 31 is lowered. As the lifter table 31 is lowered, the workpiece rail 22 is also lowered by the predetermined stroke α in FIG. 15, so that the workpiece W is positioned by the locate pin 20 while autonomously fitting to the locate pin 20 on the cassette jig 10. As a result, a positioning state in which the user is seated on the seat pad 19 is obtained. Thereafter, the pair of clampers 11 attached to the work base 8 perform a clamping operation, and the work W is transferred to the cassette jig via the drift jig 21 set in advance on the work W as shown in FIGS. 10 and firmly clamped to the work base 8.
[0037]
With the above, the positioning clamp of the workpiece W with respect to the workpiece base 8 is completed, and the workpiece W is subjected to cutting by the machining center 1 shown in FIGS. 1 to 3 while appropriately changing the posture by the tilt function of the workpiece positioning jig 3 itself. It will be. Such an operation is exactly the same even if the workpiece W has a different specification.
[0038]
When the machining by the machining center 1 is completed, the work base 8 is again indexed so as to be in the state of FIGS. 4 and 6 and stopped. At this time, the relative positional relationship between the workpiece base 8 and the roller conveyor 4 is exactly the same as that at the time of workpiece loading. Therefore, the processed workpiece W is carried out in the completely reverse procedure to that at the time of workpiece loading.
[0039]
Prior to this work unloading operation, the pair of clampers 11 are unclamped, and the lifter table 31 is moved up to the lift limit position. Thereby, as described above, the lifter table 31 lifts up the pair of work rails 22 together with the processed work W on the cassette jig 10, and the locating pin 20 and the work W on the cassette jig 10 are lifted up. While releasing the fitting, the height of the work rails 22 is made equal to the transport level of the roller conveyor 4. Thus, if the processed workpiece W is pulled out from the workpiece base 8 to the roller conveyor 4 side so as to slide on the workpiece rail 22, the workpiece W can be easily carried out.
[0040]
Here, when the specification of the workpiece W to be machined next is different from that of the previous specification, it is necessary to replace the cassette jig 10 with the corresponding specification before the next workpiece W is carried in. .
[0041]
The replacement of the cassette jig 10 is performed after the processed workpiece W as described above is carried out, and an eccentric clamp nut 14 that clamps the cassette jig 10 currently seated on the work base 8 (FIG. 8). (See FIG. 4), the lifter table 31 of the work lifter 26 is raised to the ascending limit position Q1, and the jig lift cylinder 32 on the jig frame 6 side shown in FIGS. The push rod 29 on the work base 8 side located above is pushed up by a predetermined stroke. As a result, the cassette jig 10 is completely lifted from the work base 8 together with the pair of left and right work rails 22, and as shown in FIGS. 7 and 8, the lower surface of the cassette jig 10 and the upper surface of the center portion of the lifter table 31, In addition, the jig rail 28 on the workpiece base 8 side is substantially at the same height.
[0042]
In this state, the cassette jig 10 is pulled out on the lifter table 31 along with the pair of work rails 22 while being pulled out, and is transferred to the pair of left and right jig rails 28, The cassette jig 10 can be smoothly pulled out to the roller conveyor 4 side using the jig rail 28.
[0043]
When the cassette jig 10 of the processed workpiece W has been pulled out in this way, the cassette jig 10 (a pair of workpiece rails 22 is attached in accordance with the specifications of the workpiece W to be processed next in a completely reverse procedure to the above. Are transferred onto the work base 8 and clamped. At the stage where the replacement of the cassette jig 10 is completed, the lifter table 31 on the work lifter 26 side is still at the ascent limit position Q1 even though the pair of push rods 29 are lowered by the contraction operation of the jig lift cylinder 32. Yes, as described above, the lifter table 31 is effectively used to carry the workpiece W to be processed next onto the cassette jig 10 for positioning clamping, and thereafter the same processing cycle as described above is repeated. Become.
[0044]
As described above, according to the present embodiment, when the workpiece W to be processed in the machining center 1 is manually loaded and unloaded, it is necessary to replace a part of the jig in accordance with the specifications of the workpiece W. In some cases, the drift jig 21 and the cassette jig 10 for each specification can have a very simple structure having no drive source.
[Brief description of the drawings]
FIG. 1 is an explanatory front view showing an outline of a machining process of a cylinder head by a machining center as a preferred embodiment of the present invention.
FIG. 2 is an explanatory plan view of FIG. 1;
3 is a left side explanatory view of FIG.
4 is an enlarged explanatory view of a main part of the workpiece positioning jig shown in FIG. 3. FIG.
FIG. 5 is an explanatory plan view of FIG. 4;
6 is an explanatory diagram on the right side of FIG. 4;
7 is an enlarged explanatory view of a work base portion in FIG. 4. FIG.
FIG. 8 is an explanatory plan view of FIG. 7;
FIG. 9 is an explanatory diagram of a vertical cross section of FIG.
FIG. 10 is a configuration explanatory diagram schematically showing the structure of FIG.
11 is a structural explanatory view schematically showing the structure of FIG. 8;
12 is a configuration explanatory view schematically showing the structure of FIG. 9;
13 is a schematic configuration explanatory view of only the cassette jig shown in FIG. 8. FIG.
14 is an explanatory front view of FIG. 13. FIG.
15 is an enlarged explanatory view of the main part of FIG. 9;
FIG. 16 is an enlarged explanatory view of a part B in FIG. 9;
[Explanation of symbols]
1 ... Machining center (machine tool)
3 Workpiece positioning jig
4 ... Roller conveyor
6 ... Jig frame
8 ... Work base
8a ... Reference sheet surface
10 ... Cassette jig
11. Clamper (clamp mechanism)
13 ... Reference block (positioning reference part)
14 ... Eccentric clamp nut
15 ... Jig plate
19 ... Seat pad (positioning reference part)
20 ... Locate pin (positioning reference part)
21 ... Drift jig
22 ... Work rail
26 ... Work lifter
28 ... Jig rail
31 ... Lifter table
32 ... Jig lift cylinder (Jig lifter)
34 ... Lift cylinder (lifting drive means)
W: Workpiece (cylinder head)

Claims (4)

When performing machining with a common machine tool by positioning and clamping one of multiple types of workpieces with different specifications to the workpiece base,
A cassette jig with a specific specification set so that the positioning reference part for the workpiece base is common regardless of the workpiece specification and the positioning reference part for the workpiece differs for each workpiece specification. Detachably fixed to the
While positioning the workpiece with the corresponding specifications based on this cassette jig,
Regardless of differences in workpiece specifications, the workpiece is detachably mounted with a drift jig to share the clamp part.
The drift jig as a clamping part, machine tool methods work positioning, characterized in that to clamp the workpiece to the work base in clamping mechanism provided on the work base. A workpiece positioning device for a machine tool used in the workpiece positioning method according to claim 1,
A conveyor for workpiece transfer is disposed adjacent to the workpiece base, and a workpiece lifter for raising and lowering the workpiece relative to the cassette jig is provided on the workpiece base.
This work lifter
Elevating drive means provided on the work base side;
The cassette jig is guided and supported at a position below the workpiece so as to be movable up and down, and is driven up and down by the up-and-down driving means. When the workpiece is carried in and out of the workpiece base and the conveyor, the workpiece feeding path A work rail extending toward the conveyor to function,
With
A work positioning apparatus for a machine tool, wherein the work rail is set so that a height position thereof is the same as a transfer level of the conveyor when the work rail is raised.   3. The jig lifter for pushing up the cassette jig on the work base to the same height position as the conveyor conveyance level when replacing the cassette jig is provided on the work base. Machine tool positioning device. The work base is a tilt type supported so as to be rotatable about a horizontal axis with respect to the jig frame and to be indexable at an arbitrary rotational position.
4. The work positioning device for a machine tool according to claim 3, wherein the lifting / lowering driving means and the jig lifter of the work lifter are arranged on the jig frame side.

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