WO1986004539A1

WO1986004539A1 - Oil-free cutting equipment for motor driven chain saw

Info

Publication number: WO1986004539A1
Application number: PCT/DE1986/000048
Authority: WO
Inventors: Franz Rebhan
Original assignee: Franz Rebhan
Priority date: 1985-02-12
Filing date: 1986-02-12
Publication date: 1986-08-14
Also published as: EP0214190A1; DE3504698C2; DE3504698A1

Abstract

A chain saw with an endless sawing chain comprised of articulated links is provided with guiding flaps for guiding the sawing chain into a groove of the blade of the chain saw. A driving wheel is provided at the end of the blade on the motor side to drive the chain, guided at the free end of the blade on return wheels in the form of toothed wheels. In the cutting section of the blade (2), the chain (3) is guided and supported on the points (7a) of the teeth (7) of other toothed wheels (5) mounted on roller bearings, thereby enabling to obtain a chain saw which eliminates the deficiencies of prior measures taken to reduce the friction between the chain and the blade of the saw, the side guiding and the support of the chain in the cutting section of the blade being provided for, while avoiding the friction which prior existed between the chain and the blade.

Description

oil-free cutting set for chainsaws

field of use

The invention relates to a motor chain saw with an endlessly revolving saw chain made of articulated chain links, the molded guide lugs for guiding the saw chain in a groove of a chainsaw sword, at the motor side end of which a drive wheel is provided for the chain, the deflection wheels, which are designed as a gearwheel, are guided at the free end of the sword.

State of the art

The known types of these hand saws, which are customary for cutting wood and are driven using an electric or internal combustion engine, are subject to a relatively high level of wear and tear caused by the friction in the area of their cutting links and their guidance, which wear affects the life of the cutting chain itself and the rail guiding it to such a negative extent that attempts had already been made in various ways to remedy this disadvantage, on the one hand by appropriate design of the wearing parts and on the other hand by an effective lubrication system .

However, a part of a lubricant supplied via such a system is thrown away by the chain movement of the saw chain and a certain part of it is also sucked up by the wood chips or impaired in its effectiveness by resinification.

To reduce the friction was therefore already happened schla ^¬ gen, ball bearing rollers in the individual chain links to provide the running on the guide rail so that a rolling friction takes the place of the sliding and the individual links of the saw chain touch the running rail only with their Füh approximately L appen. Although this arrangement brings about a substantial reduction in wear on the chain saw, this advantage is at least partially offset by the considerable effort associated with the roller bearing of each individual chain link.

Another proposal to reduce friction and wear on saw chains provided that the chain guide groove be made only so deep that an air gap remains between its bottom and the lower edge of the chain links and at the same time the sliding surface of the lower edges of the chain links up to the width of the chain links For guide rail walls is enlarged, so that the main pressure must be absorbed by these upper parts. With these two measures, however, basically only a spatial shift of the main wear points is achieved, the chain links still lie on the running rail, as a result of which metal surfaces rub against one another and large amounts of lubricant are necessary to avoid the risk of solid bodies Avoid rubbing and thus the annealing of the chain guide rail (DE-PS 891 921).

In addition, a long-running saw chain movement has also been recommended, in which a guide track is provided in the saw chain sword, at least in the turning area of the driven chain, via lubricant channels connected to a lubricant reservoir, which contains rolling elements that are approximately half full Rotate the speed of the saw chain freely. With this measure, the sliding friction to be reduced between the chain and its guide rail and the separate arrangement of a ö ^{'lvorratsbehälters} and an oil pump omitted. After the rolling elements are only partially covered to the outside in this arrangement, there is a risk of their movement being blocked by dust particles and wood chips entering the guideway, which in addition also absorb a part of the supplied chemical and thereby impair its effect (DE-OS 32 11 627 ).

Furthermore, a motor chain saw has already become known, from the motor housing of which is formed by the fixed connection of three adjacent lying sword plates, the outer of which project to form a guide groove over the middle plate, at the front end of the deflection spur gears serving the saw chain are mounted and at the rear end thereof a transmission of the drive energy from the motor to the chain serving sprocket is assigned, the sword being provided between the deflection gears with concave recesses over which the chain runs freely without support. Due to the lack of support, however, this is the lead. i highly difficult and the burden. for the chain due to the lack of support in the cutting area is much higher than with conventionally trained saws (DE-GM 84 20 326.9).

All of the above-mentioned constructive measures for reducing the wear of motor chainsaws have proven to be insufficient in their Wi effect, whereby it must be taken into account that they require considerable amounts of lubricants, which is not only a question of cost, but also with regard to the environmental pollution with seeping into the ground Mineral oils, including their additives, run counter to the efforts for a pollution-free work in industry, trade and household.

Task, solution, advantages

The present invention is intended to provide a motor chain saw in which all of the deficiencies described are fixed and in which the lateral guidance and support of the chain in the cutting area of the saw chain sword is maintained while avoiding the previously associated friction between chain and sword.

To achieve this object, the invention provides a motor chain saw of the type mentioned in the introduction, in which, in the cutting area of the saw blade, the chain is supported on the tips of engagement teeth of further toothed wheels with roller bearings.

With this arrangement, it has become possible to replace the support of the saw chain in the cutting area previously connected with sliding friction by a support which is only associated with rolling friction. Optimal chain guidance is thus possible, since any number of gearwheels can be arranged next to one another, the wear and / or consumption on a shimi 11e-l previously to be calculated being avoided. All that is required is the re-lubrication of the roller bearings integrated in the blade, which does not pollute the environment because the necessary grease is introduced directly into the bearings. The previous spilling and dripping of oil from the moving saw chain and its seepage into the ground is now completely ruled out. The groove in the saw blade now only serves to guide the cutting chain in a straight line, which is important for the cutting accuracy of the tool. The upper edges of the metal sheets that laterally delimit the groove are designed so that there is contact between them. the chain links and the groove edges is avoided, so that power is transmitted only via the gears.

Embodiment of the invention

In a further development of the invention according to claim 2, see that a number of concave recesses are arranged in the cutting area of the saw blade, in the transition points of which the chain is supported on the tips of the gear wheels and that in the area of the transition points the depth of the guide groove corresponds at least to the height of the guide tabs.

The advantage of this configuration is that. Also in the area of the saw blade between the gears, frictional contact between the chain and the sword can also be avoided if the chain has a play due to the decreasing tension during operation, which, with the help of the cutting forces, causes the chain to abut could lead to the saw rail. While the depth of the guide groove in the area of the gearwheels must at least correspond to the height of the guide lugs, the guide groove can have a correspondingly smaller depth within the concave recess.

It has been shown that it is particularly advantageous if, according to a further development of the invention according to claim 3, the radius of the concave recesses is selected such that the guide apples over the entire recess, even when the chain is under tension Guide groove are engaging so that the chain is securely guided over the entire recess area.

In addition, it is provided in a further development of the invention according to claim 4 that the concave sections are arranged in succession over the entire cutting area of the saw bar, the gearwheels engaging in the chain links preferably being arranged in the area of the apexes of the concave sections. As a result, the highest point of the saw blade lies at the bearing points of the saw chain, the lowest point is between the gear wheels with roller bearings and the cutting chain is no longer on the track, even with great elongation, so that the associated friction and wear can be safely avoided.

In addition, in a further development of the invention according to claim 5, the saw blade is formed by three adjacent sword plates, of which the outer sword plates protrude beyond the central plate to form the guide groove, and the gears are in a corresponding rotational movement between the outer sword plates of the recesses of the inner sword plate, which enable the gearwheels, to be arranged on the axes connecting the outer sword plates with their engagement teeth projecting over a groove edge. With this arrangement and design, a central support of the chain links can be carried out, which contributes significantly to the clean and straight-line cutting. In addition, a particularly simple and economical manufacture of the saw blade can be carried out in this embodiment of the saw blade, since the gear wheels carrying the saw chain can be installed simultaneously with the spur gear arranged in the deflection area of the saw blade.

According to another development of the invention according to claim 6, the saw blade is formed from two sword plates connected via vertically arranged crossbeams, which are arranged at a distance from one another to form an intermediate space, and the gear wheels are between the sword plates in the intermediate space which enables the gear wheels 5 to rotate Axles connecting sword plates with their engagement teeth projecting over a groove edge. With this arrangement not only a central support of the chain links can be carried out, which contributes to the clean and straight-line cutting, but it is also ensured that impurities entering the area of the gearwheels, provided that they are introduced into the intermediate space will come out of the space falling between the sword plates. In this way, contamination of the gears can be safely avoided, which leads to an increase in operational reliability. Even with this training of the saw blade, a particularly simple and economical manufacture of the saw blade can be carried out, since the toothed wheels carrying the saw chain can also be installed simultaneously with the star wheel arranged in the deflection area of the saw blade.

Another advantageous further development of the invention consists in that the saw blade and / or the traverses consist of a light metal, such as aluminum, a plastic, such as a thermoset or a suitable alloy. By using these specifically light materials, the total weight of the motorized chain saw and its manageability can be significantly improved due to the cheaper center of gravity. However, the use of these specifically lighter materials has only become possible through the new design of the saw blade, because by avoiding friction between the saw chain and the saw blade, it is no longer necessary to provide high-strength and low-wear steels, but less wear-resistant ones can also be used here Materials are used, provided they ensure the necessary load-bearing capacity. Since the heat load on the novel saw blade is considerably reduced, since, for example, annealing due to solid friction occurring between the chain and the saw blade can be avoided, materials with lower melting points can also be used. This has the advantage that when assembling such a chain sword, for example made of plastic, a firm connection can easily be carried out by heating the connection points without a total of tensions occur due to large temperature differences.

The gears are in a preferred Weiterbi the invention ldung formed so that the tips of the teeth of the gears Eingriffs¬ in the head area and in that rounded bearing surfaces between the engaging teeth neckl ^'are ausgebil¬ det. This design ensures a very favorable rolling effect of the saw chain resting on the toothed wheel tips, so that the friction losses can be kept low and the cutting set consisting of saw blade and chain can be driven oil-free. It has been shown to be an advantage of all of the above embodiments that a conventional cutting oil can be dispensed with completely and that only the bearings on which the gear wheels run must be relubricated from time to time with a grease gun. Lubrication of the saw chain is even unnecessary in professional use, since the wear of the saw chain with regard to its cutting devices is usually reached before the chain loses its mobility. For occasional use, all that is required is a conventional chain care product. A further advantage is that all the arrangements have the advantage that a larger cutting deffi ci results due to the lack of friction, although the chain lubrication required hitherto is dispensed with, since almost all of the cutting power is now available as cutting power is available. A performance increase in motor chain saws can thus be achieved while avoiding pollution of the environment.

Exemplary embodiments are described below with reference to the drawing:

1 shows a schematic side view of a motor chain saw, 2 shows a vertical cutting position of a saw blade,

3 shows a vertical section along line III-III in FIG. 1 in an enlarged view,

Fi g. 4 shows a schematic side view of a further embodiment of a motor chain saw,

F g. 5 shows a chemical side view of a further embodiment of a motor chain saw,

F g. 6 shows a schematic side view of a toothed wheel of a saw blade,

Fig. 7 shows a schematic side view of a further embodiment of a motor saw and

Fig. 8 shows a vertical section along line VIII-VIII in Fig. 7 in an enlarged view

Best way to carry out the invention

In the motor chain saw 100 shown in FIG. 1, the usual drive, control and holding elements of which are arranged in the housing 1 indicated in dashed lines, only the parts necessary for explaining the invention are shown. The chainsaw sword 2 is fastened to the housing 1 and serves to guide and hold a saw chain 3 which is moved via a drive wheel 4 connected to the drive means in the housing 1. To mount the saw chain 3, 2 gears 5 are arranged on the chainsaw sword 2 distributed over the orbit of the saw chain 3, these gears 5 running on ball or roller bearings 6 and arranged so far from the edge of the chainsaw sword 2 that they with at least one of their engagement teeth 7 in each Intervene saw chain 3, which in the exemplary embodiment shown consists of two alternately successive types of chain links, namely chain guide links 8 which have link plates and molded guide tabs, as well as chain cutting songs 9 which are equipped with sawtooth cutting approaches .

The chainsaw sword 2 is formed by three adjacent sword plates 23, 24, 25, of which the outer sword plates 24, 25 protrude beyond the middle plate 23 to form the guide groove 17. In this way, a simple design of a guide groove 17 is possible, but it can also be provided that the saw bar 2 is formed in one piece with an incorporated guide groove 17.

The gears 5 are arranged on the outer sword plates 24, 25 connecting axes 40 via bearings 6 such that the engagement teeth 7 projecting over the groove edge 17a into the chain links 8 of the saw chain 3 are supportive .ei ngrei fen. The sword plate 23 has corresponding recesses 23a, which allow a rotational movement of the gears 5 and are dimensioned such that even with the ingress of dirt particles, sawdust and the like. jamming of the gears 5 with the sword plates 23, 24, 25 can be avoided. The arrangement of the gears 5 via the bearings 6 and the axes 40 is chosen so that the links of the saw chain 3 are supported by the pinions 5 so that a distance is formed between the chain links 8 and the edges 17a of the groove 17, so that a rubbing contact between the saw chain 3 and the chainsaw sword 2 can be reliably avoided (FIG. 3).

Another special feature of the design according to the invention of a chain saw blade 2 with the gearwheels 5 in the cutting area S1, S2 consists in the shape of the saw blade 2 shown in FIG. 4 as a guide rail for the saw chain 3, which does not have a uniform shape for the rotation of the saw chain, but is of different depths, in such a way that successive concave sections 10, 11 are arranged, which differ to ensure perfect chain transport Can have length configurations so that, for example, the sections in the area of the chain inlet 12 and the chain outlet 13 have a greater length than in the cutting area of the saw chain 3. These concave recesses serve to reliably avoid contact of the saw chain 3 with the chain sword 2 in the area between two gear wheels 5, even if there is chain elongation. The radius R of the concave sections 10, 11 is selected such that the guide tabs 16 always engage securely with the tip in the guide groove 17 even when the saw chain 3 is tensioned. If the gears 5 are not too far apart, an optimal guidance of the saw chain with freedom from wear can be combined at the same time.

If necessary, the size of the gear wheels 5 for chain transport can also be selected differently depending on the requirements. The arrangement of smaller gear wheels 5 in the upper part of the chain saw blade 2 compared to larger gear wheels 5 in the area of the saw chain return at the lower peripheral edge of the chain saw blade 2 is to be only one exemplary embodiment.

1, 4 and 5, gears with relatively pointed teeth are shown. The shape of the gears depends essentially on the division of the chain and should be designed so that a favorable rolling effect of the saw chain resting on the gear tips 7 is ensured in order to keep the friction losses as low as possible. Gears 105, as shown in FIG. 6, can also be used, in which the tips 107a of the engagement teeth 107 are rounded in the head region K, so that a jam-free entry and exit into the chain parting is ensured. Chain contact surfaces A can be arranged between the engagement teeth 107.

However, the invention is not intended to be limited to the use of gearwheels of the shapes shown, which are geared to the type and pitch of the chain. However, it is essential for the functioning of the arrangement according to the invention that the gearwheels 5 are mounted in the region of the apexes 15 of the concave sections 10 and 11 of the saw blade 2, the concave sections 110, 111 being, as shown in FIG. 5, drawn in so far can that the molded chain links 8, 9 guide lugs 16 are held and guided in the area of the gears 5 in the groove 17, so that the saw chain 3 is guided in a straight line and the desired cutting performance is ensured. Between these on lageste l Len of the saw chain 3 at the apex 15, the concave sections 110, 111 are drawn in so far that the chain runs freely between its support points and does not lie on the sawing sword, even with the most extensive chains, so that even with poor maintenance , ie in the absence of (re) tensioning chains, premature wear of the saw chain 3 and the saw blade 2 can be avoided, so that chain lubrication can also be dispensed with in this embodiment and thus environmentally friendly operation is ensured.

In order to exclude the risk of the chain links 8, 9 being movably connected to one another, it is sufficient to spray the articulation points with an environmentally harmless agent, such as is used to prevent resinification of saw blades and to coat baking sheets against the sticking of dough masses is. Since a deflection wheel 115 (FIG. 1) is arranged for the deflection of the saw chain 3 at the free end 14 of the sword 2, it is ensured over the entire running range of the saw chain 3 around the saw blade 2 that a frictional contact between the chain 3 and the sword 2 is avoidable. In areas of application in which the motor chain saw is used under constant use for a short time until the cutting teeth of the saw chain 3 are worn out, a lubricant can be dispensed with entirely, since resinification and sticking of the saw chain does not occur in these periods starts.

Since the power to be applied can now be used essentially as a cutting power, there is a further effect which is environmentally friendly in that, with the same power as in the case of the conventional chain saws, the operating time is shortened can be, so that the exhaust gas and noise pollution is reduced in relation to time or that exhaust gas and / or noise reduction can be achieved with a reduced driving power.

In the embodiment shown in FIGS. 7 and 8, the chainsaw weld 2 is formed by two sword plates 24, 25 connected via vertically arranged traverses and spaced from one another, between which there is a space 123. The two sword plates 24, 25 are supported against one another via the cross members 150, but it can also be provided that only bolts are used instead of the cross members 150, or that the axes 40 between the sword plates 24, 25 are dimensioned in such a way that on one additional support can be dispensed with entirely. The gear wheels 5 therefore move freely in the intermediate space 123, so that contamination and jamming of the gear wheels 5 can be reliably avoided. In addition, the use of bolts or trusses 150 instead of the intermediate plate 23 also has the advantage of saving weight. The weight of the saw blade 2 can be optimized in any case in the chain saw according to the invention by using a light metal, such as an aluminum, a plastic, such as a thermoset, or for the saw blade 2 and / or the gear wheels 5 and / or the cross members 150 suitable alloy is used. The use of these materials still has the manufacturing advantage that a permanent connection can easily be created at the connection points by heating. For example, the axes 40 can be firmly connected to the sword plates 24, 25 by both the axes 40 and the sword plates 24, 25 being made of a plastic and the axes 40 being heated briefly, so that a firm connection is obtained. The cross members 150 or bolts used in their place can also be connected in this way to the sword plates 24, 25.

Instead of the cross members 150, differently shaped connecting elements can also be used. For optimal support of the sword plates 24, 25 against one another for the safe formation of the intermediate space 123, connecting elements with a cross or three corner cross section can be used as well as connecting elements of different shapes and cross sections, which are then used in the areas of greatest load or greatest possible deformation.

The invention is not limited to the embodiments described above and shown in the drawings. Another combination of the features and measures described is also within the scope of the invention, as is a different form of the Recesses 11, 111 or the Swertg round shape, since the friction-free steering possibility given by the gearwheels also results in greater possibilities for the formation of the sword.

Claims

1. Motor chain saw with an endlessly rotating saw chain made of articulated chain links, the molded guide lugs for guiding the saw chain in a groove of a chain saw blade, at the motor end of which a drive wheel for the chain is provided, which is free

End of the sword is guided over deflection wheels designed as gear wheels, characterized in that in the cutting area (S1, S2) of the saw blade (2) the chain (3) on the tips (7a) of engagement teeth (7) of further gear wheels (5) with roller bearings. . is supported.

2. Motor chain saw according to claim 1, characterized gekennzeich¬ net that in the cutting area (S1, S2) of the saw blade (2) a number of concave recesses (10,11) is arranged, - in their ^' transition points (15) the chain (3rd ) is supported on the tips (7a) of the gears (5) and that in the area of the transition points (15) the depth of the guide groove (17) corresponds at least to the height of the guide lugs (16).

3. Motor chain saw according to claim 2, characterized gekennzeich¬ net that the radius (R) of the concave recesses (10,11 ⁾ is selected so that the guide lobes (3) over the entire recess (11) with a tensioned chain (3) 16 ⁾ engaging in the guide groove (17).

Motor chain saw according to claim 2 or 3, characterized in that the concave sections (11) are arranged in succession over the entire cutting area (S1, S2) of the saw blade (2).

5. Motor chain saw according to one of claims 1 to 4, characterized in that the saw blade (2) by three anei nande rli egende sc hwertb Leche (23,24,25), of which the outer sword plates (24,25) to form the The guide groove (17) protrudes beyond the middle plate (23), is formed and that the gears (5) between the outer sword plates (24, 25) are in corresponding recesses (23a) of the inner sword plate (23) on the outer sword plates (24> 25) connecting axes (40) with i ren engaging teeth (7) projecting over a groove (17a) of the guide groove (17).

6. Motor chain saw according to one of claims 1 to 4, characterized in that the saw blade (2) from two vertically arranged traverses (150) connected sword plates (24, 25) which are arranged spaced apart to form an intermediate space (123), and that the toothed wheels (5) with their engagement teeth (7.) between the sword plates (24, 25) in the intermediate space (123), which enables a rotation of the toothed wheels (5), on the sword plates (24, 25) connecting axes (40) ) projecting over a groove edge (17a ^{) of} the intermediate space (123) as a guide groove (17).

7. Motor chain saw according to one of claims 1 to 6, characterized in that the tips (107a) of the engagement teeth (107) of the gears (105) in the head region (K) Z rounded and that between the engagement teeth (107) Kettenan lagef l äc en (A) trained. Motor chain saw according to one of claims 1 to 7, characterized in that the saw blade (2) and / or the crossbeams (150) consist of a light metal such as aluminum, a plastic such as a thermoset or a suitable alloy.