JPH0473035B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a rod wiper for removing dirt or dust from moving parts of a machine, such as a shaft or a piston rod, in particular a cylindrical machine part. It relates to a type in which a ring-shaped scraping tongue piece is provided which abuts on and coaxially surrounds the scraping tongue.

[Conventional technology]

Rod wipers known of this type have an uninterrupted, one-piece ring-shaped scraping tongue made of rubber-like material. The scraping tongue surrounds a movable machine part, such as a piston rod, and the scraping edge of the scraping tongue rests against this machine part.

Due to the relative movement of the machine part with respect to the rod wiper, for example a reciprocating movement, dirt or dust adhering to the shaft is scraped off from the machine part at the scraping edge of the scraping tongue.

In particular, rod wipers of this type are used in pneumatic cylinders in which the piston rod passes through the cylinder casing. In this case, it is essential to prevent foreign matter from entering the inside of the cylinder from the penetration point.

To ensure this, the scraped edges must
It must be in very tight contact with the piston rod. However, in particularly dusty environments, such as in foundries or abrasive shops or similar workshops, where the piston rod section projecting from the cylinder casing is constantly and heavily soiled, the scraped edges or scraped There is a decisive problem in that the entire removal tongue is subject to severe wear.

In another embodiment of the known rod wiper, the scraping tongues are made of a hard material, such as metal, in order to ensure a precise scraping action and at the same time reduce wear on the scraping tongues. It is manufactured from.

However, metal rod wipers have the decisive disadvantage that they are too rigid to compensate for the radial tolerances of the piston rod diameter, which may vary.

As a result, a tilting occurs between the metal scraping tongue and the piston rod, or the piston rod is severely damaged, leading to a total malfunction of the cylinder arrangement.

Conventional scraping devices press strongly against the surface of the working part of the machine to scrape it off, which has the disadvantage of damaging the edges of the sealing part, for example.

[Problem that the invention seeks to solve]

The object of the present invention is to improve the rod wiper so that the above-mentioned known problems are eliminated, so that it exhibits an excellent scraping function even in dusty environments, and which: The radial tolerance of the movable mechanical part that comes into contact with the rod wiper ensures high wear resistance and long service life, and makes it easy to manufacture. The goal is to ensure that compensation is provided without causing any harm.

[Means for solving problems]

According to the present invention, in order to solve the above problems,
The scraping tongue is made of a semi-hard plastic material or a material having similar properties, and at least the area of the scraping tongue that contacts the mechanical part has a tongue-like shape when viewed in the circumferential direction. It is divided into segments, each of which is movable independently of one another in the radial direction and relative to one another in the circumferential direction.

A first object of the present invention is to provide a rod wiper that has an excellent dust removal effect even in a dusty environment.

The second object of the present invention is to have a very low degree of wear.
Another object of the present invention is to provide a rod wiper that is easy to manufacture.

[Functions and effects of the invention]

With this configuration, the scraping tongues rest very tightly against the moving machine parts, while the individual tongue segments provide the desired local flexibility in the radial direction. It comes to show.

The advantage of the invention is that a satisfactory scraping function is ensured, while at the same time the degree of wear on the rod wiper is kept particularly low.

The material of the scraping tongue is hard enough to undergo very little wear, but is hard compared to the mechanical parts against which the scraping tongue rests and will not damage the mechanical parts.

The radial stiffness is somewhat reduced by the segmentation of the scraping tongue, so that the individual segments are relatively movable in the radial direction. However, when viewed individually, it maintains enough rigidity to be strongly pressed against the mechanical part within the range of contact with the mechanical part.

As a result of all the above, the doctor according to the invention can also be used in dusty environments where the machine parts to be scraped become very quickly and significantly contaminated. , can maintain high durability.

Furthermore, in the present invention, segmentation can be easily achieved simply by providing slits in the scraping tongue, thereby greatly simplifying the manufacture of the rod wiper.

According to an advantageous embodiment, the segmentation is carried out in such a way that the tongue segments directly abut each other:
This rod wiper can also perform a sealing function at the same time, eliminating the need for a supplementary sealing ring.

Forming slits between adjacent individual tongue segments greatly facilitates the manufacture of the rod wiper. In this case, the scraping tongues are simply manufactured without being divided and then slits are cut.

According to an advantageous embodiment of the invention, the slit is filled with a rubber-like filling material, and the individual tongue segments are filled with the rubber-like filling material without restricting their movement. connected to each other. This embodiment therefore avoids the ingress of dust or dirt into the gap.

Particularly in cylinder units equipped with a piston rod that penetrates the cylinder, it is necessary to isolate the inner chamber of the cylinder from the outside air, but with the above configuration, the rod wiper
Since the sealing function as well as the scraping function is fully demonstrated, there is no need to mount a separate seal ring, and as a result, the manufacturing cost of the cylinder unit can be kept low.

If the rubber-like filler material and the tongue segment are constructed in one piece, the filler material can be incorporated already during the production of the scraping tongue.

Furthermore, in embodiments in which the filling material and the tongue segments are configured separately but rigidly connected to each other, for example by adhesive, it is possible to produce doctors with different numbers of segments. , these segments can then be connected to each other by means of filler material, if desired.

While dividing the scraping tongue into individual tongue segments, the segment sides delimiting each tongue segment are positioned in the direction of the ring cross-section, so that the plane of these segment sides In embodiments in which the normal is oriented in the circumferential direction of the scraping tongue, a particularly simple manufacture is possible, for example using a broach or a scraping tool.

In a preferred embodiment of the invention, the scraping tongue is rigidly connected to a coaxially arranged ring-shaped jacket, which can be fixed in the casing or similar part. . This measure makes it possible to securely fix the rod wiper in position without impairing the mobility of each tongue segment.

If the scraping tongue and the jacket are constructed in one piece, they can be manufactured easily and inexpensively, for example by die casting.

If the jacket has an L-shaped cross-sectional shape, a first side of which extends radially and a second side approximately parallel to the machine part, material savings and thus Weight reduction is achieved.

The scraping tongue is fixed in the inner circumferential area of the perforated disc-shaped base, with the scraping tongue oriented in the same axial direction as the collar of the jacket in the collar-like direction, Radial mobility in the individual tongue segments is not impaired.

In a further advantageous embodiment of the rod wiper according to the invention, the scraping tongue is constructed like the outer circumferential wall of a truncated cone, the outer circumferential surface of which is attached to the abutting machine part. The diameter of the front end has been reduced.

With this advantageous measure, the scraping tongue rests against the machine part only in the area of its free end, so that a precise and thorough scraping action is achieved.

If the scraping edge that comes into contact with the machine part is integrally molded on the end of the scraping tongue on the machine part side, the range of the scraping operation can be very strictly limited. This scraping edge rests satisfactorily against the machine part and provides very good scraping results.

Note that the same thing is true when the scraping tongue has a cross section bent in a V-shape in the area where it contacts the machine part, and at that time, the tip of the V-shape extends in the circumferential direction. This is also the case for embodiments in which it serves as an existing scraping edge.

If the scraping tongue extends like a collar toward a surface of the machine part that is not to be kept clean, the scraping tongue will be lifted by dirt on the machine part and its scraping action will be interrupted. It is prevented from being weakened. Furthermore, in this embodiment, when foreign matter hits the scraping tongue, the scraping tongue is pressed even further onto the machine part, thereby intensifying the scraping action.

If a circumferential groove is formed in the area of contact with the mechanical part on the outer peripheral surface of the scraping tongue, and a tightening member such as a spiral spring is inserted into the circumferential groove,
The pressing force of the scraping tongue against the machine part is increased.

In this case, even if the scraping tongue is worn out in the area where it contacts the machine part, the scraping tongue will always be forcibly brought to its predetermined contact position by the tightening force of the tightening member. It will be done.

If the jacket is reinforced by a reinforcing ring inserted therein, a particularly reliable contact, for example in a groove provided in the housing, is ensured.
In this case, the reinforcing ring preferably has the same cross-sectional contour as the jacket, is completely inserted into the jacket and is completely surrounded by the jacket. In this way it is possible to manufacture the jacket in one working step, for example by integrally molding the jacket around the reinforcing ring.

It should be noted that the manufacture of the jacket is particularly simple if it is composed of plastic material.

According to another embodiment in which the reinforcing ring is made of metal, the strength of the doctor blade can be made extremely high.

In order for the rod wiper according to the invention to also provide an effective sealing function, it is advantageous to arrange two rod wipers axially one behind the other so that they abut against the machine part. In this case, each tongue segment on one rod wiper occupies a position approximately axially aligned with the position where the scraping tongue on the other rod wiper is divided into individual segments.

This type of arrangement is particularly advantageous if the scraping tongues are divided by gaps. If the gaps on one scraping tongue are staggered with respect to the gaps on the other scraping tongue, it is possible to effectively prevent contaminants from entering in the axial direction. .

〔Example〕

The invention will now be described in detail with reference to embodiments illustrated in the accompanying drawings.

As shown in FIGS. 1 and 2, the rod wiper of the present invention has a ring-shaped scraping tongue 1, which is coaxial with the ring-shaped scraping tongue 1. It is rigidly connected to a ring-shaped jacket 7 arranged at

The scraping tongue 1 of this rod wiper rests on a movable mechanical part 3, such as a piston rod, in which case the mechanical part 3
completely surrounded by.

The rod wiper is fixed via its jacket 7 in a groove-shaped rod wiper seat 8 provided in a casing 9, for example a cylinder casing.

The jacket 7 is configured in the shape of a bowl and has a bottom surface 19 in the shape of a perforated disc. A central perforation 18 in this bottom surface 19 allows the machine part 3 to be enclosed
has a diameter larger than the outer diameter of. The bottom surface 19 as a perforated disk is arranged coaxially with respect to the machine part 3, the plane of this perforated disk extending in the radial direction.

A cylindrical collar 20 is coaxially integrally molded on the outer peripheral surface 10 of the bottom surface 19, and the cross section of the jacket 7 is L-shaped, and the collar 20 is approximately parallel to the bottom surface 19. Constructed to sit vertically.

The mechanical part 3 passes through a perforation 22 in the casing 9 which surrounds it with play. This perforation 22 is configured to expand from the casing outer surface 23 side in a depth direction corresponding to the length of the collar 20, and its diameter 24 is approximately equal to the outer diameter of the collar 20.

This enlarged part of the bore 22 serves as a rod wiper seat 8 into which the rod wiper jacket 7 is inserted, in particular in such a way that the bottom surface 19 rests against the axial end 25 of this doctor seat 8. used.

In this case, it is advantageous if the diameter of the perforation 24 is set to be slightly smaller than the outer diameter of the collar 20 so that the jacket 7 can be press-fitted into the seat 8.

Inside the jacket 7 there is provided a coaxially arranged reinforcing ring 17 having a bowl-shaped shape, the dimensions of which are smaller than the jacket 7. This reinforcing ring 17 is embedded within the jacket 7 so that it is completely surrounded by the jacket 7. In this case, it is of course possible to attach the reinforcing ring 17 to the outer surface of the jacket 7.

The advantage of this reinforcing ring 17 is that it increases the strength of the jacket 7 and thus guarantees a very stable abutment in the rod wiper seat 8.

An inner circumferential surface range of the perforated disc-shaped bottom surface 19;
In other words, the scraping tongue piece 1 is integrally molded in a region that substantially coincides with the circumferential surface of the perforated portion 18 .
Of course, it is also possible to configure the scraping tongue 1 separately from the jacket 7, but in that case,
The scraping tongue 1 is rigidly connected to the jacket 7, for example by gluing.

The scraping tongue 1 flares out from the bottom surface 19 in the same axial direction as the collar 20. In other words, the scraping tongue 1 as well as the collar 20 of the jacket 7 point in the direction of the outer casing surface 23. The axial length of the scraping tongue 1 is equal to the length of the collar 2.
approximately equal to the axial extension of 0.

The scraping tongue 1 rests against the machine part 3 in the region of its free end 14 opposite the bottom surface 19 .

The diameter of the perforation 18 is larger than the outer diameter of the mechanical part 3, so that when viewed in its cross section in the direction from the bottom surface 19 towards the area of contact with the mechanical part 3 at its end 14, it is axially and radially An elongated oblique scraping tongue course line results.

When viewed three-dimensionally, the scraping tongue 1 is constructed like the outer circumferential wall of a truncated cone with a converging course line from the bottom surface 19 toward the end 14.

The cross section of the scraping tongue 1 is therefore substantially tapered and converges in the direction towards the end 14. The part of the end 14 that rests directly on the machine part 3 is designed as a scraping edge 6, so that the area of contact between the scraping tongue 1 and the machine part 3 extends around the circumference of the machine part 3. Limited to virtual concentric lines along the surface.

This clearly defined contact area ensures a very reliable and thorough scraping action.

The scraping tongue 1 is slit at predetermined intervals along its circumferential surface and is thus divided into individual tongue segments 4.

These slits 2 are located in planes extending in the longitudinal direction and in several radial directions of the machine part 3, the segment flanks 12, 12' circumferentially delimiting each individual slit 2 being substantially close to each other. They are located facing each other.

The depth of the individual slits 2, viewed from the end 14 of the scraping tongue 1 towards the bottom surface 19 of the jacket 7, extends over the entire axial or radial length of the scraping tongue 1. ing. However, if necessary, this slit depth may be kept small or
Alternatively, it is naturally possible to make it longer or shorter.

Next, the use and formation of the rod wiper according to the present invention will be described.

For example, mechanical part 3 as a piston rod
performs a reciprocating motion within a perforation 22 provided in the casing 9 relative to the casing 22, for example. This mechanical part 3 is guided in a bearing, not shown, so that its reciprocating movement is
It is limited by the axial extension range of the mechanical part 3.

By the way, the rod wiper according to the present invention is
In the area of the outer casing surface 23, dirt deposited on the section 27 of the machine part 3 is removed from the outer casing surface 23.
This prevents entry into the inside of the casing 26 on the opposite side. The scraping edge 6 of the scraping tongue 1, which is divided into individual tongue segments 4, which abuts the mechanical part 3 removes dirt when the mechanical part 3 moves in the direction towards the casing interior 26. Scrape from machine part 3.

If there are radial tolerances in the diameter dimension of the machine part 3, the individual tongue segments 4
By performing a pivoting movement about the area of the inner circumferential surface 11 at 9 and, as a result, imparting an approximately radial movement to the scraping edge 6, the radial crossing is compensated.

When the individual tongue segments 4 perform a radial movement, the respective circumferential spacing between two adjacent tongue segments 4 also varies simultaneously.

If the scraping tongue 1 were not segmented, an additional force would be used to move the scraping tongue 1 in the circumferential direction in order to cause a radial movement of the scraping edge 6. It will have to be expanded.

However, this is only possible if rubber-like materials are used. The possibility of using a relatively hard material for the scraping tongue 1 is a major advantage in the invention, since radial alignment to the external contour of the machine part 3 is guaranteed.

According to the embodiment shown in FIG. 3, it is possible to fill the individual slits 2 between each tongue segment 4 with a rubber-like filler material 5.

This filling material 5 prevents contaminants from entering through the slit 2 and does not impede the relative movement of adjacent individual tongue segments 4 in the radial and circumferential directions.

This embodiment is particularly advantageous because the rod
Since the wiper performs not only a scraping function but also a sealing function, there is no need to use a separate sealing ring.

FIG. 4 shows a specially shaped scraping tongue 1.
Another embodiment of a rod wiper according to the invention is shown.

In this case, the scraping tongue piece 1 has a cross-sectional shape bent into a V-shape in the area of contact with the mechanical part 3, and the tip 28 of the V-shape is visible in three dimensions. This is used as a scraping edge 6' surrounding the machine part 3.

On the other hand, a circumferential groove 15 is formed on the outer circumferential surface 13 of the scraping tongue piece 1.
The open part of the V shaped as a ring, for example a spiral spring, always presses the scraping tongue 1 and thus its scraping edge 6' against the machine part 3 in the radial direction. It is used to receive the tightening member 16 of the shape.

If such measures are taken, it is ensured that the scraping tongue 1 always remains in direct contact with the machine part 3, even if it becomes worn.

If the rod wiper according to FIGS. 1 and 2 is to also act as a sealing ring without filling the slit 2 with filler material 5, two doctors may be fitted with shafts on the mechanical part 3. They are arranged so that they are located one after the other in the direction.

In this case, two rod wipers having different outer diameters are used, and each rod wiper is inserted one after the other into the doctor seats of different diameters provided in the casing 9. It is purposeful. These rod wipers are then arranged relative to each other such that the tongue segments on one rod wiper are axially offset in front of the gap on the other rod wiper. become.

By adopting this so-called "staggered arrangement", the intrusion of foreign substances is satisfactorily avoided. When this arrangement is adopted, the respective free ends of the scraping tongues of both rod wipers are directed towards the section of the machine part which is to be cleaned.

The number of tongue segments 4 can be selected as desired. Therefore, in fields of use where only a small radial movement of the scraping tongues 1 is required, the number of tongue segments 4 can also be correspondingly reduced. It should be noted that the greater the number of tongue segments 4, the greater the radial mobility.

If a satisfactory sealing condition is to be achieved in the perforation 22 of the casing 9, a corrugated wiper, for example, located axially behind the rod wiper, ie between the doctor blade and the casing interior 26, should be It is a good idea to arrange a seal ring such as a seal ring.

The sealing lip of this sealing ring is
It extends uninterrupted and unsegmented in the same axial direction as the wiper scraping tongue 1.

In such an arrangement, the rod wiper takes over the function of cleaning the machine part 3, and the sealing ring, which is commonly available on the market, takes over the function of sealing the casing interior 26 to the outside.

[Brief explanation of drawings]

1 is a front view of a rod wiper according to the invention, FIG. 2 is a cross-sectional view of the rod wiper according to FIG. 1 along line A-A, and FIG. FIG. 4, a partial front view of an embodiment, shows a rod according to the invention.
FIG. 7 is a sectional view showing yet another embodiment of the wiper. 1... scraping tongue, 2... slit, 3...
Mechanical part, 4... tongue segment, 5... filler material, 6, 6'... scraped edge, 7... jacket, 8... rod wiper seat, 9... casing, outer periphery of 10, 19 surface, inner peripheral surfaces of 11 and 19,
12, 12'... Segment side surface, outer peripheral surface of 13, 1, free end of 14, 1, 15... Circumferential groove, 16
... Tightening member, 17 ... Reinforcement ring, 18, 19
perforation, 19, bottom of 7, 20...collar, 2
2, 9 perforations, 23...Casing outer surface, 2
4, 22 diameter, 25, 8 axial end, 26...
...Inside the casing, 27, 3 division, 28...point.

Claims (1)

[Scope of Claims] 1. A rod wiper for removing dirt or dust from a movable part 3 of a piston rod-shaped machine, which rod wiper coaxially surrounds the movable part 3 of the machine when in use. It has an annular scraping tongue 1, with which said mechanical part 3 is in contact with an annular scraping edge 6, 6', and said scraping tongue 1 has a radial direction. provided with a slit 2 for ensuring the flexibility of the scraping tongue 1, said scraping tongue 1 being made of a semi-rigid plastic resin material or a material with similar properties, said slit 2 comprising: Opening into said scraping edges 6, 6', said scraping tongue 1 is subdivided into individual circumferentially divided tongue segments 4 which are radially movable independently of one another. The slit 2 is filled with an elastomer or rubbery filling material 5, and the slit 2 is filled with an elastomer or rubber-like filling material 5.
A rod wiper characterized in that the radial movement of each adjacent segment 4 is not hindered. 2. Rod according to claim 1, characterized in that the elastomeric or rubber-like filling material 5 of the slit 2 and the tongue segment 4 of the scraping tongue 1 are integral. wiper. 3 Patent characterized in that the elastomeric or rubber-like filler material 5 of the slit 2 and the tongue segments 4 of the scraping tongue 1 are separate parts that are fixed to each other, for example by gluing. A rod wiper according to claim 1. 4 side surfaces 12,1 of each said tongue segment 4;
2' is characterized in that the normal line to the side surfaces 12, 12' is directed in the circumferential direction of the scraping tongue piece 1, according to any one of claims 1 to 3. Rod wiper. 5 Two scraping tongues 1 are coaxially provided one after the other, and each of the filled slits 2 of each scraping tongue 1 is connected to the other. A rod wiper according to any one of claims 1 to 4, characterized in that the rod wiper is arranged so as to face one of the tongue segments 4 of the scraping tongue 1.