JPH03287361A - Centerless holding device for work in internal grinder - Google Patents

Abstract

PURPOSE:To correctly rotate a work and to perform the internal grinding in a high accuracy, even in case of the body having a taper on the work outer diameter, by forming a pair of roll outer peripheral faces and a shoe with their notching, and performing the three point support of the outer peripheral face of the work with these notched end parts. CONSTITUTION:A turning force is given to a cylindrical work W as well as driving a pair of the upper and lower rolls 6, 7 with their rotation and the work W outer peripheral face is subjected to three point supporting from the radial direction by a pair of the rolls 6, 7 and a shoe 19. Moreover, the work W is held from the thrusting direction by pressing it to a front plate 20 side by a pressure rotor 27. In this case, a pair of the rolls 6, 7 outer peripheral faces and shoe 19 are formed with their notching and the outer peripheral face of the work W is supported at three points with these notch end parts 40a, 41a. Consequently, even in case of the work W having taper on the outer periphery, it can surely be held and a highly accurate internal grinding can be performed.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a centerless holding device for a workpiece in an internal grinding machine, and particularly to a device for holding a workpiece without centering it in an internal grinding machine, and in particular, it is capable of accurately holding and rotating a workpiece nine times even when the workpiece has a taper on its outer diameter. This is what I did.

(Prior Art) For example, a workpiece holding device for grinding the inner surface w1 of the workpiece W using the inner ring of the bearing as shown in FIG. 3 has conventionally been used as shown in FIG. There are 20-wheel, 1-shew, pressure rotor, and centerless holding devices.

That is, the above device has a base 1. Bearing part 2 on the - side end of
, 3, each of which has a shaft 5.5 having a pulley 4, 4 at one end thereof.
, 5 are rotatably installed horizontally with the axes of the shafts parallel to each other, and at the other end of each shaft 5. - Attached to H.

Further, as shown in FIG. 5, the support portion 3 is provided with an adjustment arm 8 integrally formed.
is carried on the pin 9 of the support block and mounted on one end of the swinging arm 10, while the other end of the swinging arm 10 is pulled downward by a spring 11, and is attached to the arm 10 on the spring connection side. The trochanter 13 is held by a threaded rod 12, and the trochanter 13 is brought into contact with a rotating cam 14 by the spring 11.

15 is located behind the above-mentioned upper and lower rolls 6.7, and a vertical plate 1
6 is a workpiece storage chute installed upright on the base 1, and the workpiece W in this chute 15 is
The workpiece that falls from the Judoro 15a onto the conveyance path 17 is moved by the rotating cam 14 to the upper roll 6.
It is configured such that it is transported to the grinding position A by a loading plate 18 that is operated in synchronization with the movement of.

Furthermore, a shoe 19 is provided at a position corresponding to the workpiece delivery opening end of the conveyance path 17, which comes into contact with the outer peripheral surface of the workpiece and participates in holding the workpiece.The workpiece contact surface of this shoe 19 is simply It has a flat surface.

Further, a front plate 20 is fixed to the vertical plate 16 of the chute 15, and this front plate 20 is connected to the lower end side of the chute 15, the transport path 17, and the part of the workpiece W transported to the grinding position A. The details of the front plate 20 are shown in FIG. 7, and a contact plate 21 with excellent wear resistance is attached to the contact surface side that comes into contact with one end surface of the workpiece W. , a through hole 22 for grinding the workpiece is formed through the front plate 20 and the abutting plate 21.

On the other hand, the front plate 20
A pressure rotor that presses the workpiece W toward the front plate 20 is provided at a position facing the workpiece W (on the other end surface side of the workpiece). This will be explained using FIG.

That is, as shown in FIG. 6, the pressure rotor is of a hydraulically driven type that supplies pressure oil to the pressure rotor main body 23 via a supply pipe 24, and this main body 2
3, as shown in FIG.
6, it is ejected toward the pressure rotor 27. As a result, the ejected pressure oil causes the circular groove 28 that accommodates the pressure rotor 27 and the pressure rotor 2
An oil film is formed between the pressure rotor 27 and the pressure rotor 27.
is configured to be supported by a type of static pressure bearing, and the pressure oil presses the pressure rotor 27 toward the front plate 20, so that the workpiece W is moved through the pressure rotor 27. The structure is such that a force in the thrust direction acts, and the workpiece W is pressed against the contact plate 21 of the front plate 20.

Next, the operation of the centerless holding device configured as described above will be explained using FIGS. 5 to 8.

In this device, first, the workpiece W in the shoe 19 is loaded onto the loading plate 18.
When loaded into the grinding position A between the upper and lower rolls 6.7, the outer peripheral surface of the upper roll 6 is brought into pressure contact with the outer peripheral surface of the workpiece W by the rotation of the cam 14, so that the workpiece W is loaded onto the grinding position A between the upper and lower rolls 6.7. Outer peripheral surface and workpiece contact surface 19 of shoe 19
It is supported at three points by a (see Figure 8).

Then, in the supported state, each of the upper and lower rolls 6.
When the roll 7 is rotated counterclockwise by an electric motor or the like, the workpiece W is rotated clockwise and the upper roll 6 is rotated counterclockwise.
Since the center of is located in front of the center of the workpiece W and the lower roll 7, the workpiece W is pressed against the contact surface 19a of the shoe 19 by a force in the radial direction and is held in the radial direction.

On the other hand, by feeding pressure oil from the supply pipe 24 into the pressure rotor main body 23, the workpiece W is pressed against the abutment plate 21 of the front plate 20 by a force in the thrust direction via the pressure rotor 27, and is pushed in the thrust direction. Retained from

After that, from the through hole 22 penetrating the front plate 20 and the contact plate 21 to the inner surface W1 of the rotating workpiece W,
It is configured to insert a grindstone (not shown) to perform internal grinding.

(Problems to be Solved by the Invention) By the way, in the workpiece W, which is the inner ring of a bearing as shown in FIG. 3, it is inevitable that the outer diameter of the workpiece will be tapered due to machining. However, in conventional devices, the outer peripheral surface of the roll that supports the workpiece at three points and the workpiece contact surface of the shoe are simply flat surfaces, so the support length in the longitudinal direction of the workpiece is long. As a result, the workpiece is directly affected by the taper of the outer diameter of the workpiece, and its rotation tends to become unstable.If the inner surface of the workpiece is ground in this condition, the shape of the inner surface to be machined will naturally be a taper that follows the taper of the outer diameter. Therefore, when continuous machining is performed, there is a problem in that variations in the outer diameter taper are directly transferred to the inner diameter taper, making it impossible to perform highly accurate internal grinding.

(Means for Solving the Problems) The present invention has been made in view of the above circumstances, and includes:
The purpose of this invention is to provide a centerless holding device that can reliably hold even a workpiece that has a taper on its outer periphery, thereby enabling high-precision internal grinding.The present invention has achieved the above-mentioned purpose. In order to do this, we rotate a pair of upper and lower rolls and apply rotational force to the cylindrical workpiece.
In this centerless holding device, the outer circumferential surface of the workpiece is supported at three points in the radial direction by the pair of rolls and shoes, and the workpiece is held from the thrust direction by pressing the workpiece toward the front plate side by the pressure rotor. It is characterized in that the outer circumferential surface of the pair of rolls and the shoe are formed with notches, and the outer circumferential surface of the workpiece is supported at three points by the notched ends.

(Function) According to the present invention, the workpiece is supported at three points by the notched ends of the pair of rolls and shoes.

(Example) Hereinafter, the main parts of the workpiece centerless holding device in the internal grinding machine according to the present invention will be explained in detail using FIG. 1 and FIG. 2.

Note that the same reference numerals are used for the same parts as in the prior art, and detailed explanation thereof will be omitted.

That is, the work W is configured to be pressed against the contact plate 21 of the front plate 20 by a force in the thrust direction via the pressure rotor 27 and held in the thrust direction, as in the conventional case.

Next, an example of a characteristic part of the present device will be described. As shown in FIG. The cross section of each of the rolls 6, 7 is formed into an L-shape as shown in FIG.

In other words, 1. In the roll 6.7 which is provided with a flange portion 40.40 and formed in a cross-sectional shape, the thickness t2 of the L-shaped cutout ends 40a, 40a is equal to the thickness t on the base side of the roll 6.7. A smaller cutout is formed, and the cutout end portions 40a, 40a of each of these L-shaped cutouts are configured to abut against the outer peripheral surface of the workpiece W.

Further, as shown in FIGS. 1 and 2, the surface of the shoe 19 facing the workpiece has the same thickness as the C-shaped notch ends 40a, 40a on the same side as the flange portions 40 and 40. By cutting out the convex portion 41 having a shape, the cross section of the shoe 19 is formed into an L-shape as shown in FIG.
The L-shaped notch end 41a is configured to abut against the outer circumferential surface of the workpiece W.

That is, according to the present embodiment, as described above, the L-shaped cutout ends 40a of the pair of rolls 6.7.

40a and the L-shaped cutout end 41a of the shoe 19, it is configured to come into contact with the outer peripheral surface of the workpiece W and support the workpiece W at three points. Since the supporting length between the outer circumferential surface of the workpiece W and the pair of upper and lower rolls 6°7 and the shoe 19 in the longitudinal direction of the workpiece W is shorter than in the past, even if there is a taper on the outer diameter of the workpiece, The workpiece is influenced by the taper and can be rotated accurately, making it possible to perform high-precision internal grinding.

In addition,. In the example described in Jz, a pair of rolls and a pair of rolls were cut out to have a cross-sectional shape, and the workpiece was supported at three points with the end portions of these cutouts. And the cross section of the shoe is formed into a trapezoidal notch, and the workpiece is held at the end of the notch.
Point support is also possible.

(Effects of the Invention) The centerless holding device for a workpiece in an internal grinding machine according to the present invention has a pair of roll outer circumferential surfaces and a shoe formed with notches as described above, and the outer circumferential surface of the workpiece is held by the notched ends. Since it is configured to be supported at three points, even if the workpiece has a taper on its outer diameter, the seven workpieces can be accurately rotated, making it possible to perform highly accurate internal grinding.

[Brief explanation of the drawing]

Figure 1 is an enlarged view showing the main parts of the present invention's holding device, Figure 2
The figure is an explanatory diagram showing the relationship between the lower roll and the shoe of the centerless holding device of the present application, FIG. 3 is a perspective view of a workpiece, FIG. 4 is a front view of a conventional centerless holding device, and FIG. FIG. 6 is an enlarged view showing the main parts of the conventional centerless holding device, FIG. 7 is an enlarged sectional view of the main parts of the pressure rotor and the front plate, and FIG. 8 is the conventional centerless holding device. It is an explanatory view showing the relationship between the lower roll and the shoe of the blank holding device. W...Work 6...-L roll 7...One lower roll...Shoe 27...Pressure rotor 40a, 41a...Notched end

Claims (1)

[Claims] 1. A pair of upper and lower rolls is driven to rotate and a rotational force is applied to a cylindrical workpiece, and the outer peripheral surface of the workpiece is supported at three points from the radial direction by the pair of rolls and shoes, and the pressure is applied to the workpiece. In a centerless holding device that holds the workpiece from the thrust direction by pressing the workpiece toward the front plate side with a rotor, the outer peripheral surface of the pair of rolls and the shoe are formed with notches, and the ends of these notches are held. A centerless holding device for a workpiece in an internal grinding machine, characterized in that the outer peripheral surface of the workpiece is supported at three points.