JPH08323623A - Cutting grinding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the weight of the whole grinder and to lengthen the useful period to improve operability in a cutting grinder with a motor arranged in a casing to drive and rotate a cutter held to a supporting arm and with a protective hood held to the supporting arm to partially cover the cutter. SOLUTION: An abrasion band 9 with strong resistance against wear is arranged on the inner circumferential surface 8 of a protective hood 5 facing a cutting edge 7 of a cutter 4. The protective hood 5 and the abrasion band 9 are manufactured from different materials.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a prime mover for driving and rotating a cutting board held by a carrying arm, and a protective hood for partially covering the cutting board. The present invention relates to a cutting and grinding machine in which the protective hood is held by a carrying arm.

[0002]

From DE-A-3916433, a cutting and grinding machine of this kind is known which comprises a prime mover for driving and rotating a cutting disk via a V-belt. The cutting board is held in the casing via a carrier arm and also has a protective hood to protect the operator from shattering grinders and grinding dust. The protective hood partially covers the cutting board. The cutting board and the protective hood are located completely in front of the front face of the casing of the cutting and grinding machine, including all the components required for mounting and driving the cutting board. As a result, the center of gravity of the cutting and grinding machine has moved forward as seen in the working direction. Care must be taken to keep the weight of the components arranged outside the casing as low as possible in order to allow ergonomically convenient handling. Otherwise, a tilting moment, which must be adjusted by the operator in order to keep the cutting grinder in a stable balance, acts around the transverse axis of the cutting grinder.

The role of the protective hood is to protect the operator from abrasive dust and sparks tangentially scattered from the cutting board. The relatively fast-spraying particles, which have a large abrasive effect, impinge on the inner circumferential surface of the protective hood.
Therefore, protective hoods are made of resistant materials such as sheet steel, but such materials have a large weight. As a result, the operability of the working machine is impaired.

Certainly, protective hoods are already made of aluminum for reasons of weight reduction, but due to the high wear they must accept that they have a short service life, which increases maintenance costs. Was there.

[0005]

SUMMARY OF THE INVENTION The object of the invention is to construct a cutting and grinding machine of the type mentioned at the beginning such that the weight of the working machine as a whole is reduced and its service life is increased in order to improve its operability. It is to be.

[0006]

SUMMARY OF THE INVENTION According to the invention, the object is to provide a cutting and grinding machine of the type mentioned at the outset with wear on the inner circumferential surface of the protective hood facing the cutting edge of the cutting machine. A wear zone is arranged which is strongly resistant to, and is solved by making the protective hood and the wear zone from different materials.

[0007]

[Operation and effect] The material of the protective hood is selected because the wear band located on the inner circumferential surface of the protective hood facing the cutting edge of the cutting board is made of a material different from that of the protective hood itself. There are no restrictions. The protective hood can be made of an extra light material with low wear resistance.
This is because the protective hood is no longer directly subjected to the action of abrasive dust and therefore has little wear due to wear and only a slight thermal load.
Protective hoods must primarily accept only their own weight as well as the weight of the wear zone secured to them, as well as the loads such as shocks that normally occur during work operations. Abrasive abrasive dust strikes the wear zone. The wear zone is made of a material that has a strong resistance to wear, and has a long service life despite a large mechanical load. The total weight of the protective hood and the wear zone is reduced as compared with the protective hood made of thin steel plate. This is because the protective hood can be thinly manufactured from a particularly light material, and the mass of the wear zone depends on the total mass of the members fixed to the carrying arm, even if a particularly heavy material is chosen. Because it is smaller than.

The attrition zone is advantageously manufactured from sheet steel and the protective hood is advantageously made of aluminum or aluminum sheet. Parts manufactured from these materials can be easily processed. This keeps production and manufacturing costs low.

The wear zone is held on the inner circumferential surface of the protective hood, in particular by means of a shape-restricting connection, in which case
It is advantageous to use riveting. Rivet splicing allows the joining of materials with very different material properties, for example different melting points. Due to the individual forces transmitted to the rivet joint, differences in the amount of stretch of the wear zone and protective hood can also be compensated.

Advantageously, the tip of the rivet of the rivet joint is located on the side of the wear zone facing the cutting board. During manufacture, the rivets are fitted radially from the outside to the inside in the protective hood, whereby the head of the rivet lies on the radially outer side of the protective hood and forms a substantially smooth surface. As a result, the protective hood is prevented from catching on the fabric, for example.

The protective hood can consist of two halves, each half being arranged with the fan-shaped base plate and at a substantially right angle to the base plate and radially outward. And a collar portion. The collars of both halves are fixed to one another, the collars expediently partially overlapping in the axial direction. In the overlapping region of both collars, at least the radially inner collar and the wear zone are connected to each other by rivets. The connection between both collars can likewise be done by riveting, in one way. In this case, the radially outer collar portion, the radially inner collar portion and the wear band are joined together by a single rivet. Alternatively, it is also possible to create the connection between both collars, in particular by welding.

Further constructions and advantageous aspects are mentioned in the subclaims.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. A cutting and grinding machine 1 is shown in FIG. The cutting and grinding machine 1 has a prime mover arranged in a casing 2. The prime mover is configured as an internal combustion engine in the illustrated embodiment. A first grip 22 extending in the longitudinal direction of the work machine is arranged in the casing 2,
The grip 22 is provided with a throttle lever device 24 for starting the prime mover. Another grip 23 is arranged in front of the first grip 22 when viewed in the working direction 25. The grip 23 is located substantially in a plane perpendicular to the working direction 25. The cutting and grinding machine 1 is held and operated by an operator by the grips 22 and 23.

At the free end of the carrying arm 6 arranged in the casing 2, a rotatively driven cutting board 4 is arranged. The cutting board 4 is driven by the prime mover via the V-belt 3 guided by the carrying arm 6. The carrying arm 6 projects beyond the front of the casing 2 or the grip 23 in the working direction 25 such that the cutting disc 4 is completely in front of the cutting grinder casing.

The cutting board 4 is covered by a protective hood 5 over a circumference angle of approximately 200 °, whereby
The possibility that polishing dust and sparks or the part of the cutting board that scatters or shatters in the tangential direction of the cutting board 4 hits the operator and is injured is prevented. Abrasive dust, which has a large abrasive effect, hits the inner circumferential surface of the protective hood 5 and loses kinetic energy during a collision. And the polishing dust is the protective hood 5.
Through the open side and falls downwards.

To form the wear resistant protective hood 5,
On the inner circumferential surface 8 of the protective hood, a wear band 9 is arranged on the side of the cutting board 4 facing the cutting edge 7. The wear zone 9 is formed so as to have a strong resistance to polishing dust that collides at high speed. The protective hood 5 and the wear zone 9 are made of different materials. The protective hood 5 is then advantageously made of a material which is particularly lighter than the wear zone 9. The protective hood is advantageously made of aluminum or an aluminum plate, on the contrary, the wear zone is advantageously made of sheet steel. This combination, as well as the use of commercial materials that can be easily processed, makes it possible to thinly form the protective hood 5 made of aluminium, whereby the weight of the protective hood is increased. Has the advantage that A wear strip made of sheet steel protects the inner circumferential surface of the protective hood from abrasive dust. Therefore, there is no need to worry about wear of the protective hood. On the other hand, the wear band made of thin steel plate can be manufactured at low cost and has a strong resistance to abrasion. As a result, the service life of the protective hood and the working machine is extended. The weight of a thin wear band is
It is negligibly small compared to other members extending forward of the casing of the cutting and grinding machine, such as the carrier arm 6 and the cutting board 4. By reducing the total mass of the members arranged in front of the casing, the tilting moment about the transverse axis of the work machine is also significantly reduced or completely offset. Thereby, the operability of the cutting and grinding machine is enhanced.

As indicated by the broken line in FIG. 1, a wear band 9 extends around the entire circumference of the inner circumferential surface 8 of the protective hood 5.
As a result, the protective hood 5 is protected from polishing dust on the entire inner circumference of the cutting board 4 on the side facing the cutting edge 7. As a result, abrasive dust that is drawn into the inner chamber of the protective hood 5 over a relatively large angular range by the rotating cutting board 4 also does not damage the protective hood.

It is also advantageous to arrange the wear zone only in a partial area of the inner circumference of the protective hood, in particular in the area of the protective hood on the casing side of the cutting and grinding machine. FIG. 2 shows a protective hood 5 with a wear zone 9 fixed to the inner circumferential surface 8.
FIG. The wear zone 9 is expediently fixed to the inner circumferential surface of the protective hood by means of a form-locking connection, in particular a rivet seam 10. Dispersed on the circumference,
Advantageously, approximately eight rivet joints 10 are provided at regular intervals, so that the wear zone 9 bears flatly on the circumferential surface 8 over the entire inner circumference of the protective hood 5.
The rivets 11 of the rivet seam 10 are expediently punched out during manufacture as perforated rivets through the protective hood 5, whereby the rivet head 12 of the rivet lies on the radially outer side of the protective hood. With perforated rivets, the protective hood and wear zone do not need to be perforated for rivets. The rivet head 12
It is embedded in the wall of the protective hood and forms a smooth surface (see Figure 3). The shaft 13 of the rivet 11, which is preferably embodied as a hollow rivet, penetrates the wall of the protective hood 5 and the wear zone 9. At that time, a rivet tip 14 is formed at the free end of the shaft. The rivet tip 14
It has a wall region that is bent radially outwards, which wall region creates the shape-restrictive connection of the rivet joint. The rivet 11 is expediently formed as a hollow rivet from the outside through the wall of the protective hood and the wear zone. The axis of the hollow rivet extends conically when viewed from the rivet head 12, the rivet wall being widened so that the connection is maintained even if the cutting disc side of the rivet tip wears.

The hollow chamber inside the hollow rivet contains the punched-out material of the protective hood and wear zone. These materials in the hollow chamber of the hollow rivet on the side of the cutting board 4 facing the cutting edge 7 protect the rivet 11 from abrasion by abrasive dust. Thereby, the life of the rivet joint is extended. The rivet tip 14 projects from the surface of the face 15 of the wear zone 9 facing the cutting disc and is shaped by the rivet set during the manufacture of the protective hood. Thereby a shape-constrained bond is created.

As shown in FIG. 3, the protective hood 5 consists of two halves 16,17. These halves 16, 17 are
It is arranged so as to enclose the cutting board, and is almost flat on the cutting board
They are fixed to each other in eight areas. Each half 1
Reference numerals 6 and 17 include fan-shaped substrates 16a and 17a, and one collar portion 16b and 17b that extends substantially at right angles to the substrates and is positioned on the outer side in the radial direction. The collar is then expediently created by deforming the substrate. Each substrate has a radius just slightly larger than the cutting board 4. As a result, the radially inner surface of the protective hood, which is formed by the collar, is located at a distance concentric to the cutting edge 7 of the cutting board 4. Collar portions 16b of both halves 16 and 17,
17b partially overlaps axially in the region of the plane 18 of the cutting board. In that case, the overlapping region has a spread b.
In the expansion b, the collar portion is not curved in the axial direction. The attrition zone 9 also advantageously has at least a width b, the overlap region and the attrition zone extending substantially symmetrically with respect to the cutting plane 18.

The width of the wear zone is adapted to the distance between the two substrates 16a, 17a lying parallel to each other, at the transition between the substrate and the collar, outside the non-curved overlap region. It is also advantageous for the wear zone to have a curvature adapted to the transition.

The halves 16, 17 can have different thicknesses, the supporting half 16 being expediently thicker than the opposite half 17. In the embodiment shown in FIGS. 2 and 3, a rivet 11 joins both collars 16b, 17b and the wear zone 9 together. At this time, the rivet head 12 of the rivet 11 is embedded in the wall of the collar portion 17b on the outer side in the radial direction.

Instead of hollow rivets, other forms of rivets can be used, such as round head rivets, blind rivets, or straight belt rivets. Although not shown, the connection can also be performed by screws and nuts.

FIG. 4 shows another bonding possibility in the overlapping area. The rivet 11 is driven through the collar 16b and the wear zone 9 prior to the assembly of both protective hood halves 16,17. After that, the collar portion 17b of the second protective hood half portion 17 is restrained by the collar portion 16b of the first protective hood half portion 16 on the outer side in the radial direction.
Is combined with The bond is then advantageously created by welding. Since both halves 16 and 17 are made of the same material and therefore have the same melting point, welding of both halves is possible without problems. Weld seam 26
Is in contact with the end face of the radially outer collar portion 17b and is inclined like a slope to the transition region of the radially inner collar portion 16b. As a result, a uniform transition between both collars is created, avoiding the formation of dirty edges.

The connection of both collars can also be created by soldering or gluing. The radially outer collar 17b covers the rivet head 12 of the rivet 11 which is driven through the wall of the collar 16b, whereby the rivet 11 is completely covered with respect to the outside. This measure method is particularly advantageous in the following cases. That is, the walls of the protective hood are made thicker, which makes the rivet method for joining both collars, including the attrition zone, particularly expensive for rivets incorporated in the drilling method. This is the case.

The erosion zone and the radially inner collar portion 16b can be joined by a rivet punching method according to an embodiment not shown. In that case, the metal plate portion in which the wear band is stamped and bent is the collar portion 1.
Guided through 6b and used for riveting.

The base plate 16a of the protective hood half 16 facing the carrying arm 6 is provided with a number of finger-like punched-out portions 19 extending in the radial direction (FIG. 1, FIG. 4, FIG.
And FIG. 5). The embossment 19 enhances the stability of the advantageously thin protective hood, which is embossed from the base plate 16a and is held on the carrier arm 6 via the base plate 16a. The punched-out portion 19 extends outward in the radial direction from a central space 20 located at the center of the substrate 16a. A drive shaft (not shown) passes through the space 20. The cutting board 4 is fixed to the drive shaft so as not to rotate relatively, and the drive shaft is
It is driven by the belt 3. A space is similarly provided in the center of the opposing substrate 17a, and the drive shaft can penetrate through the space similarly.

The finger-shaped punched-out portion 19 is raised on the surface of the substrate 16a. A total of four punched-out portions are provided, which taper towards the radially outer edge of the protective hood 5. The embossed portion has a substantially trapezoidal cross section.

[Brief description of drawings]

FIG. 1 is a side view of a cutting and grinding machine having a protective hood and a cutting board.

FIG. 2 is a cross-sectional view of a protective hood having an attrition zone located on the radially inner surface.

FIG. 3 is a partially enlarged view of a region of the rivet joint shown in FIG.

FIG. 4 is a cross-sectional view corresponding to FIG. 2 of the connection between the protective hood half and the wear zone of another embodiment.

FIG. 5 is a side view of a protective hood.

[Explanation of symbols]

 4 Cutting board 5 Protective hood 6 Carrying arm 7 Cutting edge 8 Circumferential surface 9 Abrasion zone 10 Riveting joint 11 Rivets 14 Rivet tip 15 Abrasion zone surface 16 Protective hood half 16a Substrate 16b Color part 17 Protective hood half 17a Substrate 17b Collar portion 18 Cutting plane plane 19 Ejection portion b Width of wear band

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Joachim Hoffmann, Federal Republic of Germany Day 73207 Plochingen Anne Frank Weg 79

Claims (11)

[Claims] 1. A protective hood having a prime mover for driving and rotating a cutting board (4) held by a carrying arm (6), the protective hood (1) partially covering the cutting board (4). 5) In a cutting and grinding machine having a protective hood (5) held on a carrying arm (6), the protective hood (5) facing the cutting edge (7) of the cutting board (4) The wear-resistant zone (9), which is highly resistant to wear, is arranged on the inner circumferential surface (8) of the housing, and the protective hood (5) and the wear-resistant zone (9) are made of different materials. A cutting and grinding machine characterized by 2. Grinding and grinding machine according to claim 1, characterized in that the wear zone (9) is held in the protective hood (5) by a shape-restrictive connection, in particular a rivet joint (10). . 3. A rivet (1) of a rivet joint (10)
Cutting and grinding machine according to claim 2, characterized in that the rivet tip (14) of 1) is located on the side (15) of the wear zone (9) facing the cutting board (4). 4. A protective hood (5) has two halves (16,
17), each half (16, 17) of which is a fan-shaped substrate (16a, 17a) and a substrate (16a, 17a).
and (a) a collar part (16b, 17b) which is arranged substantially at right angles to and located radially outwardly, and collar parts (16b, 17b) of both halves (16, 17).
Cutting grinder according to one of claims 1 to 3, characterized in that the two are fixed to each other. 5. The collar portion (16b, 17b) of both halves (16, 17) has an overlapping region extending axially in the region of the cutting board plane (18).
The cutting and grinding machine according to claim 4. 6. Cutting and grinding machine according to claim 5, characterized in that the width (b) of the attrition zone (9) substantially coincides with the width of the overlapping region. 7. Cutting grinding according to claim 4, characterized in that the wear zone (9) is fixed in a shape-restricted manner on the collar (16b) located radially inward. Machine. 8. One of the claims 4 to 7, characterized in that both collar parts (16b, 17b) of the halves (16, 17) are connected to each other, in particular welded to each other. The cutting and grinding machine described. 9. The substrate (16a) of the protective hood half (16) facing the carrying arm (6) is provided with a finger-like punched-out portion (19) extending substantially in the radial direction. Cutting grinder according to one of claims 1 to 8, characterized in that 10. Cutting according to one of claims 1 to 9, characterized in that the protective hood (5) is made of a material which is particularly lighter than the wear zone (9) and in particular consists of aluminium. Grinding machine. 11. Cutting and grinding machine according to claim 1, characterized in that the wear zone (9) is made of sheet steel.