JP5809342B1 - Screw grinding machine - Google Patents

Abstract

A screw grinding apparatus capable of highly accurate and highly efficient thread grinding is provided. A through-feed centerless screw grinding apparatus includes a grinding wheel 2 having a plurality of ring-shaped protrusions 2a having the same interval as the pitch of a spiral screw 4 formed on an outer peripheral surface, a grinding wheel and an adjusting wheel 1 Between the feed roller 7 to be fed to the grinding region 3 between the feed member and the grinding wheel, and the spiral groove of the spiral screw when the spiral groove 8 of the spiral screw is brought into contact with the ring-shaped protrusion of the grinding wheel And a guide member 9 having a curved surface shape following the spiral groove, and the guide screw contacts the spiral groove of the spiral screw while the spiral screw is fed to the grinding region by the feed roller. Thus, the spiral screw grinds the spiral groove with the ring-shaped protrusion of the grinding wheel while the advance with respect to the rotation angle is controlled to be constant. [Selection] Figure 1

Description

  The present invention relates to a screw grinding apparatus for grinding a helical screw, and more particularly to a screw grinding apparatus capable of automatically and continuously subjecting a screw having a spiral groove formed therein in a continuous and highly accurate manner. .

Conventionally, a cylindrical grinding machine is usually used for high-precision thread grinding. In this cylindrical grinding machine, a material such as a round bar is clamped to center and processed one by one. However, although it is a high-precision thread grinding process, it takes a lot of work to set up one by one, so a screw grinding apparatus by centerless grinding has been devised that does not require the work of setup (Patent Document 1). reference).
This thread grinding machine uses a grinding wheel with a number of ring-shaped ridges formed by centerless grinding while continuously feeding the round bar with a blade and an adjusting grindstone while rotating it through the through-feed method. It is excellent and can be threaded at a low cost with high efficiency. In this case, as the bulk material used, a non-hard material such as ferrite that is easy to process is selected.

JP-A-10-118843

The conventional through-feed type centerless screw grinding device described above makes it possible to efficiently machine a large amount of non-hard material Muku round bars and rough finished screw materials that are easy to machine. Met. However, the conventional centerless screw grinding apparatus is not necessarily sufficient in terms of screw machining accuracy and surface roughness accuracy, and is a difficult machining method for hard materials that are difficult to grind.
In other words, in the conventional centerless screw grinding device, the grinding wheel formed with the ring-shaped ridges grinds the thread groove, and the processed thread groove itself serves as a guide to feed the workpiece in the traveling direction. Because of the configuration, if the screw groove shape collapses or the screw groove dimension expands beyond a predetermined value for some reason, the accuracy of the entire screw is reduced. It was. Also, it is not efficient to grind from a hard material.

  The present invention has been made in view of the circumstances described above, and an object thereof is to provide a screw grinding apparatus that enables screw grinding with high accuracy and high efficiency.

As a result of diligent research in view of the above problems, the present inventor has separated the function of the guide by the grinding wheel with respect to the thread groove, and by providing a dedicated guide member, enables accurate screw feeding, high accuracy and high It came to devise the screw grinding device which can perform thread grinding efficiently.
That is, the present invention provides a through-feed centerless screw that is supported by a blade and an adjustment grindstone, and in which the adjustment grindstone grinds with a grinding wheel while rotating the spiral screw about the axis while the spiral screw in which a spiral groove is formed in advance is supported. In the grinding apparatus, a grinding wheel in which a plurality of ring-shaped protrusions having the same interval as the pitch of the spiral screw are formed on the outer peripheral surface, and a feeding member that sends the spiral screw to a grinding region between the grinding wheel and the adjustment wheel, Between the feed member and the grinding wheel, and located on a virtual spiral that extends the spiral groove of the spiral screw when the spiral groove of the spiral screw comes into contact with the ring-shaped protrusion of the grinding wheel; A guide member having a curved surface shape following the spiral groove, and the guide member contacts the spiral groove of the spiral screw while the spiral screw is fed to the grinding region by the delivery member. It allows the helical screw is characterized in that the grinding by the ring-shaped ridge of the grinding wheel and the spiral groove while being controlled to lead of the rotation angle is constant.
With such a configuration, thread grinding can be performed with high accuracy and high efficiency.

In addition, the guide member includes an adjustment mechanism that adjusts the position of the spiral screw in the radial direction and / or the axial direction.
Thereby, the guide of the spiral screw by a guide member can be performed correctly.

  Further, the plurality of ring-shaped protrusions of the grinding wheel are characterized in that grinding is continuously performed from roughing to finishing according to the traveling direction of the helical screw by sequentially changing the protruding dimension of each convex portion. .

  Further, the guide member is characterized by comprising a female screw screwed with the helical screw.

It is explanatory drawing which shows the 1st Example of the screw grinding apparatus of this invention. It is explanatory drawing which shows the 1st Example of the screw grinding apparatus of this invention. It is explanatory drawing which shows the 2nd Example of the screw grinding apparatus of this invention.

  Hereinafter, an embodiment for carrying out a screw grinding apparatus according to the present invention will be described in detail with reference to the accompanying drawings. FIGS. 1 to 3 are diagrams illustrating embodiments of the present invention. In these drawings, the same reference numerals denote the same components, and the basic configuration and operation are the same. To do. In the present embodiment, a ball screw will be described as an example of a screw to be ground. However, the type of screw is not limited to this, and various screw-shaped spiral screws such as a triangular screw and a trapezoidal screw may be used. Is also corresponding.

<Configuration>
As shown in FIG. 1, the first embodiment of the screw grinding apparatus of the present invention includes an adjustment grindstone 1 (or an adjustment grindstone), a grinding grindstone 2 (or grinding grindstone wheel) facing the adjustment grindstone 1, and an adjustment grindstone 1. And a grinding wheel 3 (not shown) that is positioned between the grinding wheel 2 and supports the workpiece, and a grinding area 3 is formed. In order to feed the helical screw 4 before grinding to the grinding area 3, a feeding roller 7, which is located in the front stage in the horizontal direction of the grinding area 3 and includes a driving roller 5 and a driven roller 6, A guide member 9 is provided that is fixedly positioned between the grinding areas 3 and guides the axial progress of the spiral screw 4 that rotates in contact with the spiral groove 8 of the spiral screw 4 before grinding.

  The spiral screw 4 of this embodiment is provided with a single spiral groove 8 regardless of its material, but the spiral screw to be ground by the screw grinding apparatus of the present invention is not limited to this, A screw having a plurality of spiral grooves may be used. Further, the spiral screw 4 of the present embodiment is a right-hand screw as shown in FIG. 1, but a left-hand screw can be used. Furthermore, the cross-sectional shape of the spiral groove 8 is also substantially semicircular in this embodiment, but is not limited to this, and may be any concave shape.

  The delivery roller 7 includes a drive roller 5 and a driven roller 6, while a drive roller 5 having a drive unit rotates the spiral screw 4, and the rotating spiral screw 4 rotates a free driven roller 6 having no drive unit. The spiral screw 4 is fed in the direction of the grinding area 3 by a slight inclination of the drive roller 5 or the like.

The grinding wheel 2 has a plurality of ring-shaped ridges 2a formed at the same pitch (preset pitch) as the spiral groove 8 of the spiral screw 4 to be ground. The plurality of ring-shaped protrusions 2a can grind the spiral groove 8 of the spiral screw 4 at the same time over the entire length thereof.
The plurality of ring-shaped ridges 2a of the grinding wheel 2 may be configured to continuously grind from roughing to finishing according to the traveling direction of the helical screw 4 by sequentially changing the protruding dimension of each convex portion. It ’s good.

The guide member 9 has a convex shape in which the lower end portion 9a thereof follows the concave shape of the longitudinal section of the spiral groove 8 of the spiral screw 4, and in this embodiment, the guide member 9 has a hemispherical shape with a smooth surface. The guide member 9 can smoothly guide the spiral screw 4 by contacting the spiral groove 8 without rattling.
The guide member 9 is disposed on a grinding wheel slide (not shown) so as to move integrally with the grinding wheel 2 and matches the pitch of the ring-shaped protrusions 2a of the grinding wheel 2, that is, the grinding wheel 2 Is set to a position that is an integral multiple of the pitch from the ring-shaped ridge 2a before (left end in FIG. 1). However, adjusting the pitch in this case means that when the guide member 9 is positioned on the contact line between the grinding wheel 2 and the spiral screw 4, the position is an integral multiple of the pitch. When rotated to a position deviated from the contact line, for example, a position opposite to a blade (not shown), it is not a position that is an integral multiple of the pitch, but a position advanced or retreated by the rotation, that is, the spiral groove 8 of the spiral screw 4. The tip portion 9a of the guide member 9 is positioned at a position on a virtual spiral that extends the spiral groove 8 of the spiral screw 4 when the ring is in contact with the ring-shaped protrusion 2a of the grinding wheel 2.

Further, the protruding dimension in the axial direction of the distal end portion 9 a of the guide member 9 is equivalent to the protruding dimension of the ring-shaped protrusion 2 a of the grinding wheel 2, and the distal end portion 9 a of the guide member 9 hits the thread of the spiral screw 4. It is good also as a structure provided with biasing members, such as a spring, in a base end part so that it can escape in this case and it can escape to an outer diameter direction.
Further, as a mechanism for finely adjusting the mounting position of the guide member 9, an adjustment mechanism for finely adjusting the distal end portion 9a in the radial direction (vertical direction in FIG. 1) of the spiral screw 4 and the axial direction (horizontal direction in FIG. 1). (Not shown) is provided on the base end side, and the position is finely adjusted according to the actual workpiece.
By setting the guide member 9 in this manner, the spiral screw 4 guided by the guide member 9 and fed in the traveling direction causes the spiral groove 8 to be formed in the ring-shaped protrusion 2a of the grinding wheel 2 at an accurate feed pitch while rotating. Matched and sent without blurring.

<Operation>
The operation of the screw grinding apparatus of the present invention having such a configuration will be described in detail below.
First, FIG. 1 shows a state before processing, and the spiral screw 4 is sent to the right in FIG.
The spiral screw 4 is rotated before the contact with the adjusting grindstone 1 while the guide member 9 abuts from the tip of the spiral groove 8 while rotating, and rotates while the guide member 9 abuts on the spiral groove 8 as it is. Proceed in the direction.

Following this, the spiral screw 4 contacts the adjustment grindstone 1 and is similarly driven to rotate in the opposite direction to the adjustment grindstone 1, and abuts so that the tip 9a of the guide member 9 fits into the spiral groove 8. Thus, the spiral screw 4 advances in the axial direction without sliding or dancing while being regulated by the guide member 9.
The ring-shaped protrusion 2a at the left end of the grinding wheel 2 is aligned with the spiral groove 8 at the tip of the spiral screw 4 because the guide member 9 is set in advance at the same position as the spiral pitch of the spiral screw 4. It is to be ground.

  In this way, the spiral screw 4 that rotates and advances while the spiral groove 8 is being ground by the ring-shaped protrusion 2 a of the grinding wheel 2 causes the second ring-shaped protrusion 2 a next to the grinding wheel 2 to move to the spiral groove 8. Then, as shown in FIG. 2, it proceeds to the last ring-shaped protrusion 2a at the right end. Then, the spiral screw 4 moves from the grinding area 3 and moves to the next process. At the same time, the next spiral screw is conveyed to the grinding area 3.

FIG. 3 shows a second embodiment of the thread grinding apparatus according to the present invention, and a convex guide in which the distal end portion 9a of the first embodiment described above follows the concave shape of the longitudinal section of the spiral groove 8 of the spiral screw 4. Instead of the member 9, a female screw type guide member 21 having a screw thread shaped to be screwed into the spiral groove 8 of the spiral screw 4 is used.
The guide member 21 is formed with a spiral groove that engages with the thread of the spiral screw 4 in order to guide the spiral screw 4 to be processed in the axial direction without rattling, and the spiral screw 4 that advances while rotating. In order to catch and engage the tip smoothly, a tapered portion may be formed at the tip, and some springiness and flexibility may be provided.
Further, like the guide member 9 of the first embodiment described above, as a mechanism for finely adjusting the mounting position, the guide member 21 is arranged in the radial direction (vertical direction in FIG. 3) of the spiral screw 4 and the axial direction (FIG. 3 is provided on the base end side to finely adjust the position according to the actual work piece.

  The screw grinding apparatus of the present invention can be used in the processing industry for grinding a helical screw precisely and efficiently.

DESCRIPTION OF SYMBOLS 1 ... Adjusting wheel 2 ... Grinding wheel 2a ... Ring-shaped protrusion 3 ... Grinding area 4 ... Spiral screw 7 ... Feeding roller 8 ... Spiral groove 9 ... Guide member 9a ... Tip part 21 ... Guide member

Claims (4)

In a through-feed centerless screw grinding apparatus in which a spiral screw in which a spiral groove is formed in advance is supported by a blade and an adjustment grindstone, and the adjustment grindstone is ground by a grinding grindstone while rotating the spiral screw around an axis,
A grinding wheel formed on the outer peripheral surface with a plurality of ring-shaped protrusions at the same interval as the pitch of the helical screw;
A delivery member that sends the helical screw to a grinding area between the grinding wheel and the adjustment wheel;
Between the feed member and the grinding wheel, and located on a virtual spiral that extends the spiral groove of the spiral screw when the spiral groove of the spiral screw comes into contact with the ring-shaped protrusion of the grinding wheel; A guide member having a curved surface shape following the spiral groove,
While the spiral screw is fed to the grinding region by the delivery member, the guide member comes into contact with the spiral groove of the spiral screw, so that the advance of the spiral screw with respect to the rotation angle is controlled to be constant. A screw grinding apparatus for grinding a screw, characterized by grinding with a ring-shaped protrusion of a grinding wheel.   The screw grinding apparatus according to claim 1, wherein the guide member includes an adjustment mechanism that adjusts a position in a radial direction and / or an axial direction of the helical screw.   The plurality of ring-shaped ridges of the grinding wheel are continuously ground from roughing to finishing according to the traveling direction of the helical screw by sequentially changing the protruding dimension of each convex portion. The thread grinding apparatus according to 1 or 2.   The screw grinding apparatus according to claim 1 or 2, wherein the guide member is formed of a female screw that is screwed with the helical screw.