JPH0413073Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] This invention relates to a telescopic cover that telescopically slides over the machining bed surface of a machine tool to protect the bed. The present invention relates to an improvement in sliding rollers disposed on each of a plurality of cover bodies constituting a pick cover.

[Conventional technology]

As is well known, the machining bed surface of a machine tool is protected by a so-called telescopic cover in which a plurality of large and small cover bodies are telescopically extendable.

Here, to explain the positional relationship between the machining bed surface of the machine tool and the telescopic cover, the second
As shown in the figure (partially cutaway perspective view), in order to slide the box-shaped telescopic cover B, which has a plurality of large and small cover bodies that can be expanded and contracted in a telescoping manner, on the processing bed surface A of the machine tool. , a sliding roller C is disposed at a suitable position below it. Here, the sliding roller used is generally a needle bearing or, as shown in FIG. The material of its construction was mainly steel. In recent years, machine tools have become larger,
The current situation is that the telescopic cover itself has become larger as work speeds have increased, and that it has been forced to slide at higher speeds on its bed surface.

[The problem that the idea attempts to solve]

Therefore, as the telescopic cover becomes larger, it inevitably becomes heavier, but since the telescopic cover is manufactured by sheet metal processing and is not a sufficiently rigid body, the telescopic cover may slide on the machined bed surface. When moving, the entire weight of the cover may be concentrated on the pair of sliding rollers due to vibration or distortion of the cover, so the sliding rollers must also be strong to withstand that weight. becomes. As mentioned above, such sliding rollers are of needle bearings and are not aligned, and may be caused by the sliding of the telescopic cover or the installation condition of the rollers (slight errors during installation). (Due to this)) The axis of the bearing is tilted, the contact surface of the roller to the bed surface is tilted and touches the bed surface, and an extreme load is placed on one end of the needle, resulting in a significant loss of the original life of the bearing. Become. As a result of the so-called misalignment, the surface pressure load also increases, and as mentioned above, the material cannot be said to be less hard than the material of the bed surface, so the bed surface may be bitten and the surface pressure may increase. This tends to cause damage to the surface and shortens the life of the sliding roller itself. Furthermore, an unbalanced load is applied to the bearing itself, which greatly shortens the life of the bearing, resulting in the bearing not turning (destroying) and the rollers chewing up the sliding surface of the machined bed surface. In order to satisfy all of the above problems, the diameter of the sliding roller inevitably tends to be large. However, due to the nature of the telescopic cover being stored in a nested manner, the sliding rollers disposed below the telescopic cover must be as small as possible, otherwise, when all cover bodies are stored in a nested manner. There is an inconvenience in that the sliding rollers get in the way and the cover body cannot be completely stored. In short, pole bearings or roller bearings are small in diameter and cannot handle high loads, so they do not meet the above objectives.Therefore, regardless of high loads, they must be as small as possible, and in practice, small diameter needle bearings are used. is preferred. Furthermore, since the hardness of the sliding surface of the sliding roller on the processing bed surface is generally softer than that of the same roller, frequent sliding of the same roller causes peeling phenomenon, and as mentioned above, this phenomenon is further exacerbated by the contact of the roller with the shoulder. Since this phenomenon becomes noticeable, the outer circumferential surface of the roller that comes into contact with the machined bed surface is required to be made of a material with a lower hardness than that of the machined bed surface.

This proposal was devised in view of the above-mentioned problem, and regardless of the size of the telescopic cover and the high-speed sliding, the axis of the sliding roller is tilted while the telescopic cover is sliding. The purpose is to ensure that even if the roller is tilted when installed on the cover, the surface pressure load on the bed surface will not fluctuate compared to when it is normal, so it will not scratch the bed surface and cause damage, and the life of the roller will be extended. shall be.

[Means to solve the problem]

In order to achieve the above-mentioned objective, the main structure of the present invention is a sliding roller disposed on a telescopic cover in which a plurality of large and small cover bodies are telescopically extendable to cover the processing bed surface of a machine tool. , an inner race and an outer race are provided concentrically within the roller;
A needle bearing is interposed between the inner and outer races, and a coating layer made of a metal material such as brass, which is softer than the constituent material of the machined bed surface, is attached to the outer periphery of the outer race. This telescopic cover protects the bed surface of a machine tool having a sliding roller whose radius of curvature is approximately equal to the radius of the outer diameter of the roller.

[Effect]

The telescopic cover of the present invention constructed as described above has a small contact area with the bed surface even if the axis of the sliding roller is tilted relative to the bed surface during high-speed driving. There is almost no change compared to normal conditions, the vector direction of the load points toward the bearing center point, and the bearing rotates on the bed surface without causing any change in the contact surface pressure received from the bed surface. It can continue sliding, does not scratch the bed surface, and has little negative impact on the life of the bearing.

〔Example〕

Next, one embodiment of the present invention will be described based on the attached drawings.

FIG. 1 is an enlarged sectional view of the sliding roller of the telescopic cover of the present invention.

In the drawings, reference numeral 1 denotes a sliding roller body in which a needle bearing is installed.
That is, 2 is an outer race of the bearing, 3 is an inner race, and 4 is a needle interposed between the inner and outer races. By using needle bearings, it is possible to handle high loads and instantaneous impact loads, and the diameter of the roller can be made compact. Reference numeral 5 denotes a coating layer coated on the outer periphery of the outer race, which forms the sliding roller main body 1. This coating layer 5
The constituent material is at least softer in terms of physical properties than the constituent material of the machining bed surface of the machine tool (normally, in the industry, FC material is hardened by machining and quenching). For example, an alloy such as brass is used.
The radius of curvature in the axial direction of the outer circumferential surface of the coating layer 5, that is, the roller body 1, is formed by a radius 6 having a radius of curvature approximately equal to the radius of the outer diameter of the roller (rotation radius), as is clear from FIG.

As described above, in the roller of the present invention, the outer periphery in the axial direction of the coating layer formed on the outer peripheral surface of the outer race is formed in a radius, and this radius is formed in a radius of curvature that is approximately equal to the roller radius (rotation radius). The roller is coated with a coating layer, so that even if the contact angle of the roller with the bed surface is slightly tilted, the contact area with the bed surface will hardly change, and the load vector direction is centered on the bearing. It is configured to point in a direction approaching the direction of the point.

The coating layer 5 may be provided by, for example, attaching a ring-shaped member made of an alloy such as brass and having an outer circumferential surface formed with the above-mentioned radius to the outer periphery of the outer race of a conventional sliding roller.

[Effect of idea]

As described above, the roller of the present invention has a radius of curvature on the outer circumferential surface of the outer race of the sliding roller, where the radius of the outer circumference in the axial direction is approximately equal to the roller radius (rotation radius).In other words, the vector direction of the load is at the center of the bearing. Since the coating layer is formed with a radius pointing in the direction approaching the point, (a) even if the contact angle of the roller with the bed surface is slightly tilted (in other words, it will not be biased due to irregular movement of the roller, etc.) Even when the load is applied, the contact area with the bed surface hardly changes, and the contact pressure is always at the same level, and the contact pressure can be lowered even when the weight increases due to the larger cover. Since the vector direction of the load points toward the center point of the needle bearing, the inherent life of the bearing is hardly reduced. This means that even if there is a slight installation error in the needle bearing, there will be little adverse effect on the life of the roller and bearing.
(b) Moreover, since the sliding roller in the present invention is made of a metal material that is softer than the material that makes up the bed surface, the roller rotates without nibbling the bed surface. ,
Damage to the bed surface cannot occur either.

In addition, if the coating layer on the outer periphery of the outer race of the sliding roller (bearing outer periphery) is made of plastic, chips that have been hardened by machining and scattered on the sliding surface of the bed will bite into the coating layer. It is conceivable that the bed surface may be scratched and scratched during sliding, but in the case of this proposal, the coating layer is made of a material (softer) with lower hardness than the bed surface, but metals such as brass Since it is made of aluminum, there is no such fear at all.

(c) Furthermore, in this proposal, even if there is a slight error in the angle at which the sliding rollers are attached to the bottom surface of each cover body that makes up the telescopic cover,
Since there is no problem in the sliding of the sliding roller on the bed surface, the installation specifications are not as strict as in the past, and the installation workability is also improved.

[Brief explanation of drawings]

Figure 1 is an enlarged cross-sectional view of the sliding roller of the telescopic cover of the present invention, Figure 2 is a partially cutaway perspective view showing the positional relationship between the machining bed surface of the machine tool and the telescopic cover, and Figure 3 is the telescopic cover. FIG. 2 is an enlarged sectional view of a conventional sliding roller disposed at a proper position below each cover body of the cover. 1...Sliding roller body, 2...Outer race, 3
...Inner lace, 4...Needle, 5...Coating layer,
6...R, 7...Flat surface, A...Processed bed surface, B...Telescopic cover, C...
Sliding roller.

Claims (1)

[Scope of utility model registration request] It is a sliding roller installed in a telescopic cover, which has multiple large and small cover bodies that cover the machining bed surface of a machine tool and can be expanded and contracted in a telescoping manner. A race is provided, and a needle bearing is interposed between the inner and outer races, and a coating layer made of a metal material such as brass, which is softer than the constituent material of the machined bed surface, is attached to the outer periphery of the outer race, and the outer periphery of the coating layer is A telescopic cover for protecting the bed surface of a machine tool comprising a sliding roller whose radius of curvature in the axial direction is approximately equal to the radius of the outer diameter of the roller.