JPS5882644A - Attaching structure of nut for precision feed screw - Google Patents

Abstract

PURPOSE:To make high precision table feed possible by attaching via the heated and hardened layer of rigid urethane, a nut engaged with a precision feed screw used for driving a static pressure slide table of a machine tool, to a bracket fixed on the table. CONSTITUTION:A nut 7 with which a precision feed screw 1 used for driving the static pressure slide table 3 of a machine tool is engaged is inserted into a bracket 5 for supporting the nut fixed on a table 3 while leaving several mm. gaps in the axial and radial directions respectively, and an adhesive 15 for metal is applied on the respective opposing faces 6, 9, 11-14 of the bracket 5 and the nut 7. Then, by injecting thermosetting rigid urethane 16 into the gap among the opposing faces and heating and hardening it, the bracket 5 and the nut 7 are fixed in a body.

Description

[Detailed Description of the Invention] This invention provides an
This invention relates to a mounting structure for a nut that fits into a tight feed screw.

Conventionally, there are two methods for connecting a nut to a table: one in which the nut is fixed directly to the table, and the other in which the nut is fitted with high precision in the axial direction and the center of the screw is allowed to swing freely 360 degrees. there were. The latter seems to be capable of highly accurate axial transmission without being affected by screw runout, but it has not been possible to eliminate errors in the fitting squares in the axial direction. In addition, a thrust air bearing can be used to apply a preload in the axial direction to eliminate errors.The device has become very expensive.

This invention solves these problems and allows the screw feeding nut of the ultra-precision slide unit to be attached to the table.
During Lfc, it is related to the structure of connecting the nut to the table so that the vibration of the screw and nut is not directly transmitted to the table. - The hole for attaching the nut and the nut of the bracket that is fixed to the table and incorporated into the Naratra are connected. A gap of several U is created between them in the axial and radial directions, and adhesive is applied to the facing surfaces of the bracket and nut facing this gap, and liquid thermosetting hard urethane is injected into the gap. This invention relates to a nut mounting structure that is heated and hardened so that the nut is elastically supported by the bracket.

An embodiment of the present invention will be described below with reference to the drawings. A precision feed screw (1) such as a ball screw or a static pressure screw
The nut (2) is screwed into the static pressure slide table (3) [inserted into the hole (6) of the bracket (5) fixed with the bolt (4). . In this embodiment, the nut (2) has a flange (
7) is integrally protruded, and a 7 flange (8) is inserted into the outer diameter surface (9) K at the other end in the axial direction and is integrally fixed to the nut with screw α1. Therefore bracket (5)
is sandwiched between the collar portion (7) and the flange (8) from both sides in the axial direction. However, between the radially opposing surfaces of the bracket and the nut, i.e., the inner diameter surface of the bracket hole (6) and the outer diameter surface (9) of the nut, and the axially opposing surfaces of the bracket and the nut, i.e., the axial end surface of the bracket. αυ, a′
4, the inner surface (6) of the flange (7) of the nut, and the flange (8).
), a gap 1 of about the size of n number of fermentations is created between the inner surfaces a◆. Then, the inner diameter surface of the hole (6), which is the opposing surface of the nut (including 7 flange) and the bracket in the radial and axial directions, the outer diameter surface (9) of the nut, and the flange 7
The inner surface of the lunge (B), Q4, is pre-applied with a metal adhesive (2) such as Buxane Primer (trade name).

Next, as shown in the figure, there is a gap in the radial and axial directions between the nut and the bracket, there is no contact surface between the nut and the bracket, and there is no restraint against the axial movement of the screw and table. Inject liquid urethane←Q into the gap between the nut and the bracket while keeping it in a clean state. This urethane has thermosetting properties. After injecting the urethane QQ', heat the nut and bracket to about 100℃ to inject the urethane α.
When Q is cured, a heat-cured layer Ct* of hard urethane with elasticity is formed. And urethane hardened layer QQ
Since it is adhered to the mounting nut and bracket using a metal adhesive, the nut and bracket are connected to each other via the hardened layer while maintaining appropriate elasticity.

According to this invention, the nut is connected to the bracket fixed to the table through the hardened urethane layer with a gap 1, so that when the feed screw (1) is driven, the nut is connected to the bracket fixed to the table (3). It is possible to slide the nut without causing any scratches due to nVC at the mounting position. In addition, the hardened urethane layer αQ sandwiched between the nut and bracket has good vibration absorption properties, allowing quiet feeding. By appropriately changing the solidification hardness of urethane, it is possible to obtain a spring effect that meets the requirements of each type of comb.

Moreover, since the urethane is soaked in oil resistance, the nut will not be installed incorrectly over a long period of time, and vibrations of the feed screw and nut can be completely prevented from being transmitted to the table.

Note that this invention is not limited to the above embodiments,
For example, it is possible to provide a flange or a flange on the bracket side to support both axial end surfaces of the nut.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of an embodiment of the present invention, and FIG. 2 is a partially enlarged view of section A in FIG. (1)...Feed screw (2)...Nut (3)
...Table (5) ...Bracket (6),
(9), αη, CL1. (6), α→... Opposing surface α$
... Adhesive α0 ... Heat-cured layer of urethane Patent attorney Junji Kawachi

Claims (1)

[Claims] The nut that is threaded onto the feed screw is inserted into the nut holding bracket fixed to the table in the axial and radial directions.
It is inserted with several gaps in between, metal adhesive is applied to each opposing surface of the bracket and nut, and liquid thermosetting hard urethane is injected into the gap between the opposing surfaces. A mounting structure for a nut for a Seiko feed screw for driving a static pressure slide table, which is characterized by forming a heat-hardened layer of.