JPH0129002Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is used in a crank pin lathe that turns the crank pin portion of the crank shaft of multiple types of internal combustion engines. ) has a predetermined crankpin eccentricity.

(Prior art) A conventional crankpin lathe of this kind, in which a headstock is installed on the bed, supports a main shaft having a transverse rotational axis on the headstock, and supports it on a chuck provided at the end of the main shaft. A holder is attached so that the radial position corresponding to the amount of eccentricity of the crank pin of the crankshaft can be arbitrarily selected, and the journal parts at both ends of the crankshaft are gripped by the holder, and the crank supported by the holder is attached. The crank pin of the shaft is aligned with the axis of the main spindle and rotated together with the main spindle, and a column installed on the bed guides the feed stand in a direction perpendicular to the axis of the main spindle on the bed. In a crank pin lathe that turns the crank pin part using a cutting tool installed at the tip of a fixed tool rest, the crankshaft may be replaced for some reason while being carried from the carry-in position to the processing position. If you start machining as is, the crankshaft will become defective. Therefore, in preparation for such cases, the machine is equipped with a device that determines whether the workpiece gripped by the chuck has a predetermined crankpin eccentricity or not, and prevents incorrect machining of the crankshaft. There is. In the conventional workpiece discriminating device shown in FIG. 4, a contact 3a at the lower end of a swinging lever 3, which is pivotally supported via a pin 2 on a support lever 1 which is held in a fixed position during discrimination, is connected to the workpiece. A light pressure is applied to the crank pin portion C1, and the swing lever 3 is caused to swing by utilizing the revolution movement (eccentric movement) of the crank pin portion C1 that occurs when the amount of eccentricity of the crank pin is not a predetermined value, and the upper end of the swing lever 3 is A detection switch 4 that detects the movement of the crank pin is used to determine whether the workpiece gripped by the chuck has a predetermined eccentricity of the crank pin. However, in this conventional device, the crank pin portion C
1, the contact 3a is pressed against the rake surface 2 of the cutting tool 24.
Since it was arranged on the 4b side, it was easily affected by chips and the like. Therefore, the support lever 1 is pivotally supported by the pivot 5, the lowering of the feed base is temporarily stopped in a state in which the contact 3a is located on the diameter line of the crank pin portion C1, that is, in a state in which no machining is performed, and the crank pin is The workpiece discrimination device is rotated in the T direction to perform discrimination, and after discrimination, the workpiece discrimination device is moved to position A by a cylinder device (not shown) via an arm 1b fixed to the support lever 1 and a link 6. For this reason, machining cannot be performed during that time, resulting in a longer cycle time.Moreover, in order to release the contact 3a, the support lever 1, arm 1a,
A pivot 5, a link 6, a cylinder device, a support bracket for these, etc. were required.

(Purpose of the invention) The purpose of the invention is to provide a workpiece discrimination device with a short cycle time and a simple structure.

(Structure of the invention) In order to achieve the above object, the present invention provides a crankpin lathe of this type, in which a swinging lever substantially parallel to the guiding direction of the feed stand is pivotally supported on the tool rest by a horizontal pivot; The lateral position of one end of the swinging lever on the cutting tool side is approximately the same as that of the cutting tool, and the longitudinal position is opposite to the rake surface of the cutting tool, and a contact is installed at the tip thereof, and when moving the feed base, The contactor is provided on the crankpin part side with respect to the cutting tool in the moving direction of the feed base so that the cutting tool turns the crankpin part after the contactor passes the crankpin part, and This workpiece discrimination device is characterized in that a detection device is provided at the other end of the movable lever to detect movement of the swing lever beyond a predetermined value.

(Effect of the invention) The present invention can determine whether or not the workpiece gripped by the chuck has a predetermined crankpin eccentricity during the machining cycle for turning the crankpin part. The cycle time can be shortened, and since a cylinder device for swinging the swing lever is not required, the structure of the device is simple and can be provided at low cost.

(Embodiment) FIGS. 1 to 3 show an embodiment of the present invention. As shown in FIG. 1, a pair of headstocks 12 facing each other on the left and right sides on the bed 11 of the crankpin lathe 10
Each headstock 12 supports a pair of main shafts 13 that rotate about a common horizontal axis, and is rotationally driven by a main shaft driving motor 14.
A chuck 1 is provided at the opposite end of each main shaft 13.
5 are attached to each of them, and a crankshaft (workpiece) C is gripped via a holder 16, which will be described later, so that its crank pin portion C1 is coaxial with the main shaft 13. bed 11
Column 21 is installed on the left and right in the upper rear part,
The column 21 guides a feed table 22 in a central portion above the bed 11 so as to be movable in the vertical direction. A cutter stand 23 is fixed to the front lower part of the feed stand 22, and the crank pin portion C1 is turned by the cutter 24 provided at the lower left and right ends of the cutter stand 23.

As shown in Figures 2 and 3, each chuck 1
5 are provided with radial notches 15a at the same angular phase position, and a receiver 16 is mounted so as to be movable in the same radial direction. A gripping portion 16a is provided at the center of the tip of the receiver 16, and the journal portions C2 at both ends of the crankshaft C are held in the gripping portion 16a.
The crank pin portion C1 is fixed to the receiver 16 by a gripping device (not shown) with the angular phase of the crank pin portion C1 matching the radial direction. The type of crankshaft C is determined in advance by a workpiece identification device etc. before being transported.
Based on the discrimination signal, the receiver 16 is positioned at a predetermined radial position, and the chuck 15 is inserted through the receiver 16.
When the crankshaft C is gripped, the axes of the left and right crank pin portions C1 to be machined are aligned with the axis of the main shaft 13.

Two cutters 24 are provided on the left and right lower end portions of the cutter stand 23 fixed to the feed stand 22, corresponding to the positions of the left and right crank pin portions C1, and are fixed with clamps 25 and clamp bolts 26.

During machining, the main shaft 13 rotates in the T direction (FIG. 2), and the crank pin portion C1 also rotates coaxially with the main shaft 13. Next, the feed table 22 is lowered together with the cutting tool rest 23, and the tip 24a at the tip of the cutting tool 24 turns the crank pin portion C1. In the embodiment, the front side of the cutting tool 24 is the rake surface 24b for turning.
It is.

The above structure and operation are basically the same as those of conventional crankpin lathes.

In this embodiment, as shown in FIGS. 2 and 3, the swing lever 31 is pivotally supported on the tool rest 23,
Prior to turning, the contact 33 at the lower end is brought into contact with the crank pin C1, and a detection device 40 provided near the upper end determines whether the crankshaft C gripped by the chuck 15 is a predetermined one.

A groove 27 is vertically passed through the back surface of the tool rest 23 in contact with the feed base 22, and the feed base 2 is inserted into the groove 27.
A swing lever 31 is provided that extends along the guide direction 2, and is pivotally supported on the tool stand 23 by a pivot shaft 32. The lower end of the swinging lever 31 that projects downward from the tool rest 23, that is, one end 31a on the side of the tool 24, is bent in the horizontal direction, and a contact 33 made of a roller pivotally supported by a lateral pin 34 is provided at the tip. The lateral position of this contactor 33 is made to match the lateral position of one of the cutting tools 24. The contactor 33 is positioned in the front-rear direction so as to be in contact with the crank pin portion C1 on the opposite side of the rake surface 24b of the cutting tool 24.
To avoid being affected by chips during turning of the crank pin part C1 by No. 4. Further, the contactor 33 is provided on the crank pin portion C1 side with respect to the cutting tool 24 in the moving direction of the feed base 22. An adjustment bolt 35 and an abutment bolt 3 are installed at the front and back of the other end of the swing lever 31, that is, the upper end 31b that projects upward from the tool rest 23.
6 so that the length can be adjusted freely, and then tighten the abutment bolts 3.
The tip of the lever 6 comes into contact with a stop bolt 37 fixed to the feed base 22 to determine the reference position of the swing lever 31, and the adjustment bolt 35 drives a detection device 40, which will be described later.

The main body 41 of the detection device 40 is attached to the feed base 22 via a bracket 47, and the detection switch 4
2 and the actuating member 43. Actuation member 43
is movable in the longitudinal direction with respect to the main body 41, one end of which contacts the roller 42b at the tip of the lever 42a of the detection switch 42, and the other end of which comes into contact with the tip of the adjustment bolt 35 mentioned above. The side surface of the actuating member 43 is pressed by a pressing spring 45 via a sliding piece 44, and once the actuating member 43 is pushed by the swing lever 31 via the adjustment bolt 35 and moved, it is then swung by a return spring 46. Even when the lever 31 returns, the actuating member 43 remains in the moved position.

Next, the operation of this embodiment will be described.

As described above, when the tool rest 23 descends, the contact 33 first comes into contact with the rear side of the crank pin portion C1.
(Illustrated with two-dot chain line in Figure 2. Corresponding parts are indicated by '')
). In this state, the cutting tool 24 is not yet in contact with the crank pin portion C1. If the crankshaft C has a predetermined crankpin eccentricity and therefore the crankpin C1 is coaxial with the main shaft 13, the crankpin C1 only rotates and does not revolve. The contactor 33 is not pushed and the swing lever 31
Since the upper adjustment bolt 35 and the operating member 43 do not press the roller 42b of the detection switch 42, the detection switch 42 does not operate. The tool rest 23 continues to descend, the contact 33 passes behind the crank pin C1, the tip of the cut tool 24 comes into contact with the crank pin C1, and a predetermined turning process is performed on the crank pin C1. If the crankshaft C does not have a predetermined crankpin eccentricity, the crankpin C1 will revolve as the main shaft 13 rotates, and the swing lever 31 will periodically swing beyond the set initial amount. move. Therefore, the roller 42b of the detection switch 42 is also pushed by a predetermined amount or more, and the detection switch 42 is activated.
A necessary warning is issued and the crankpin lathe 10 is stopped to prevent erroneous machining. Once the detection switch 42 is activated, it is maintained in the activated state by the actuating member 43, the sliding piece 44, and the pressing spring 45, but the same holding action can also be performed by other methods, such as electrical means.

In the above embodiment, the radial position of the receiver 16 is automatically moved and adjusted to accommodate different crankshafts W, but the invention is not limited to this.
By replacing the receiver 16 with another receiver 16, it is possible to correspond to a different type of crankshaft W. Further, in the above embodiment, a pair of left and right headstocks 12 is provided, but the present invention is not limited to this.
2 may be placed on one side to support the crankshaft in a cantilevered manner.

(Effects of the Embodiment) In the above embodiment, the contact 33 at the lower end of the swinging lever 31 pivotally supported on the tool holder 23 is brought into contact with the rear side of the crank pin portion C1 during machining and feeding of the tool holder 23. Distinguish the workpiece gripped by the chuck 15,
Subsequently, the contact 33 is passed through by machining feed, and the crank pin portion C1 is turned by the cutting tool 24, so that no extra process is required between the identification of the workpiece and the turning process, thereby shortening the cycle time. be able to. Moreover, a cylinder device for releasing the swing lever 31 is not required, and the structure of the device is simple and inexpensive.

[Brief explanation of drawings]

FIG. 1 is an overall front view of a crankpin lathe equipped with an embodiment of the present invention, FIG. 2 is an enlarged side sectional view taken along the - line of FIGS. 1 and 3, and FIG.
The front view of the figure, FIG. 4, is a view corresponding to FIG. 2 of the conventional example. Explanation of the code, 10... Crank pin lathe, 11
...Bed, 12... Headstock, 13... Spindle, 1
5...chuck, 16...receiver, 21...column, 22...feeding stand, 23...tool stand, 24...
Cutting tool, 24b...rake face, 31...swinging lever, 31a...one end on the cutting tool side, 31b...other end,
32... Pivot, 33... Contact, 40... Detection device, C... Crankshaft (workpiece), C1... Crank pin portion, C2... Journal portion.

Claims (1)

[Scope of utility model registration request] A headstock is installed on the bed, and a main shaft having a horizontal rotation axis is mounted on the headstock, and a chuck provided at the end of the main shaft has a diameter corresponding to the eccentricity of the crank pin of the crankshaft to be supported. A holder is mounted so that the directional position can be arbitrarily selected, the journal parts at both ends of the crankshaft are gripped by the holder, and the crank pin part of the crankshaft supported by the holder is aligned with the axis of the main shaft. A column installed on the bed guides the feed stand in a direction perpendicular to the axis of the main spindle on the bed, and a cutter provided at the tip of a tool stand fixed to the feed stand rotates the crank. In a crank pin lathe for turning a pin portion, a swinging lever substantially parallel to the guiding direction of the feed stand is pivotally supported on the tool rest by a horizontal pivot, and a swing lever on the cutting tool side of the swing lever is supported by a horizontal pivot. The lateral position of one end is approximately the same as that of the cutting tool, and the longitudinal position is opposite to the rake face of the cutting tool, and a contact is installed at the tip thereof, and when the feed base moves, the contact is attached to the crank pin. The contactor is provided on the side of the crank pin section with respect to the cutting tool in the moving direction of the feed base so that the cutting tool turns the crank pin section after passing through the swing lever, and the contactor is provided at the other end of the swinging lever. 1. A workpiece discrimination device comprising a detection device for detecting movement of a moving lever beyond a predetermined value.