DE3319875A1 - Electropneumatic hammer drill - Google Patents

Abstract

An electropneumatic hammer drill in which the drive piston and open percussion member are accommodated in a cylindrical guide tube which is centred in the drill casing is to be improved such that the design and arrangement of the guide tube is less expensive and more favourable conditions with respect to the quiet running of the percussion mechanism are obtained. For this purpose, it is proposed that the two end faces of the guide tube possess axial play and the securing of the guide tube against axial displacement is effected by means of resilient elements which are supported, on the one hand, on casing-side fixed abutments and, on the other hand, directly or indirectly on the guide tube (Fig. 1). <IMAGE>

Description

-L ic ε. n't ia
Patent - Verwaltungs - GmbH
Theodor-Stern-tfai 1, 6D0D Frankfurt / M.

ES 83/6

Electropneumatic stretcher hammer

The invention relates to an electro-pneumatic En Bahrham ^! mer, in which the drive sleeve and the free-floating Srhlagkörperj are housed in a cylindrical guide tube which is centered in the j hammer housing.

In known rotary hammers of this type, the guide tube is a component of the housing or at least secure against displacement in the bzuj. at the Housing attached. As a result, the ones that occur in hammer drilling Shocks, blows and vibrations, also dampened, practice: Transfer the drilling tool to the guide tube. This leads to vibrations in the striking mechanism and thus also to a certain uneven running. In addition, the known types of design or arrangement of the guide tube, such as its attachment mi Using a flange, relatively expensive. ί

i The invention has for its object to improve the smoothness of the pneumat tables impact mechanism of the subject electro-pneumatic hammers and j at the same time to enable a cost-effective arrival j order and design of the guide tube. ;

To solve this problem, the invention provides that the two j The end faces of the guide wheel have axial freedom of movement! and the securing of the guide tube against axial displacement i is carried out by resilient elements which are located on the housing-side fixed abutment and on the other hand directly or support it indirectly on the guide tube.

It has proven to be especially effective, ^di? resilient elements in each case as at least one D-ring arranged between two ring disks and the stops on the guide tube are each implemented by a locking ring which is inserted in a recess made in the outer wall of the guide tube. -r ** COPY]

BAD ORIGINAL _u _ '

The invention udrd explained below with reference to the drawing.

They show: FIG. 1 a partial longitudinal section through the

Impact mechanism containing gear part of an electropneumatic stretcher hammer ,

Fig. 2 is a view along the section A-B through Fig. 1,

3 shows a modification of the solution according to Figures 1 and 2.

In Fig. 1, 1 denotes the cylindrical guide tube which is centered in the housing 2 in its rear region by the honeycomb 3 and in the region of its side facing the tool by a bearing bracket 5 provided with air channels k. In the guide tube 1, which has an axial freedom of movement, the drive piston is tightly and slidably guided. The ßntriebskolben is set in a periodic reciprocating motion by means of an eccentric 7, which is mounted on the shaft 8, which is driven by the electric motor, not shown.

The impact body 9 slides freely in the guide tube 1 and is pneumatically moved back and forth by the drive piston 6 via the compression medium air. During the working stroke, the accelerated bearing body 9 strikes a striker 1D, which in turn acts on the rear face of the tool (not shown) or of the tool holder. The drive of the tool is via the spindle sleeve -12 provided with a gear 11, ie the "." Gear 11 via a gearwheel 11 via an integrated gearwheel gearwheel, possibly with the interposition of a leading gearwheel in rotation is moved. " ~ '^! \

BATH ORIGINAL

"- '*' - .; ■ 33Ί9875

E5 S3 / 6

In the area of the front third of the guide tube 1, this ES is provided on its outer circumference with an incision for receiving a locking ring, likewise in the area of its rear third. The two retaining rings are designated by 13 and 13 '. A ring washer 1it and 15 comes to rest on each of the two locking rings. Each of the two ': lif iingscheiben and 15 is spaced a second ring Scheib · Ii + ¹ and 15' associated with LUDbei the annular disc 15 'is supported on the end face of the hub 3 and the annular disc Ik' at the k with air channels provided bearing bridge 5 for Plant is coming. _s In the intermediate space between the two annular discs Ik, 14 'and the two annular discs 15 _T 15' is in each case a resilient element 16, 16 'in the form of an O-ring. Instead of a D-ring, a plate spring or the like could also be used.

The cylindrical guide tube 1 is thus elastically supported and can move axially within the scope of the spring travel. On the one hand, this results in the transmission of vibrations and structure-borne noise reduced to the hammer mechanism in hammer drilling operations and on the other hand, the prerequisite for είπε cost-saving training of the striking mechanism within the framework of the training and storage of the guide tube.

In the hub 3, not shown, air flow channels are attached, which the cylinder interior with the drive-side part of the gearbox housing.

From Fig. 2, the entire support of the washer 1 * + is on the bearing bridge 5 provided with air ducts, which at the same time the tool-side centering of the guide tube ?: 1 takes over.

In the embodiment according to FIG. 3 is in the rear . A resilient element is provided in the area of the guide tube 1, as a cylindrical and thus reinforced damping element 17 is designed that there are t ionen in hammer drill knnnstriik where the residue. ' Energy through the cylindrical guide tube 1 dissipated wi :::, tJis able to absorb this energy. COPY,

ORIGINAL BATHROOM ^l

ES 63/6

There is between the outer jacket surface of the damping element 17 and the centering ribs 18, which also serve as an abutment for this element, are provided with a sliding bush 19, the centering ribs delimiting air ducts. The spring-elastic element 17, which is embodied as a hollow cylinder is secured against axial displacement by a locking ring 20, which is inserted into one in the outer wall of the guide tube attached puncture is used. The resilient element 17 is positively locked by the two disks 21, 22 held.

Instead of the locking ring 20 and the disc 21 can Stop of the resilient element 17 also by a be embodied shoulder attached to the cylindrical guide tube.

In some cases it may prove sufficient to use the guide tube 1 can only be assigned a single elastic mounting within the meaning of the invention.

The guide tube 1 can consist of an unhardened steel tube, its inner sliding surface thanks to a special surface treatment is made abrasion or wear resistant, for example by deganitriding or by a Tenifer treatment.

Claims (7)

L i c. β η. t i. ξ ... P-tent - V rescue? - - limb H ooi dor-Scorp-Kri Ί, GGUO Frankfurt όό V ΕΞ S3 '/ S' 'Frankfurt, den. 26th 5-15.83 claims 1.) Electropneumatic hammer drill, in which the drive piston and the free-flying impact body in a cylindrical Guide tube ■ are housed in the hammer housing? centered is, characterized in that f.] the two end faces of the guide tube have axial movement clearance "and the securing of the 'guide tube against axial displacement takes place by means of resilient elements, which are on the one hand art .. housing-side fixed abutments and on the other hand directly lean indirectly on the guide tube. 2 '. Rotary hammer according to claim 1, characterized in that the Guide tube with ana etching on its outer circumference. is provided as an abutment for the spring-elastic Elenete to serve. 3. Rotary hammer according to claim 1, characterized in that the resilient elements each by at least one between two ring disks arranged G-ring and the stops on the guide tube / 4furcn one in one in the outer landing of the Guide tube attached puncture inserted locking ring are embodied, with the one ring washer on Hammer housing and the other washer supported on the locking ring. ■ H. rotary hammer according to claims 1 and 2, characterized in that the resilient elements are embodied by taller springs. 5. Rotary hammer according to claims 1 to '♦, characterized gekennzeichne ι , -that the guide tube in its uerkzeuciseiten and in its rear area by a spring table element against axial displacement is secured. ^j COPY BATH ORIGINAL 3319375 6. Rotary hammer according to claim 1, characterized in that the guide tube at least in its rear area on a 'absorbing the recoil energy of the guide tube' resilient element is supported, which in turn is attached to the Guide tube centering ribs comes to rest. 7. Rotary hammer according to one of several of the preceding claims, characterized in that the guide tube consists of unhardened steel and its inner guide surface ■ "a surface treatment that increases abrasion resistance is subjected.