EP0671511B1 - Schwenkbagger - Google Patents

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Publication number
EP0671511B1
EP0671511B1 EP19950103250 EP95103250A EP0671511B1 EP 0671511 B1 EP0671511 B1 EP 0671511B1 EP 19950103250 EP19950103250 EP 19950103250 EP 95103250 A EP95103250 A EP 95103250A EP 0671511 B1 EP0671511 B1 EP 0671511B1
Authority
EP
European Patent Office
Prior art keywords
boom
lower boom
swing
opening angle
front attachment
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP19950103250
Other languages
English (en)
French (fr)
Other versions
EP0671511A2 (de
EP0671511A3 (de
Inventor
Shinya Okabe
Nobumitsu Sakuma
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Construction Machinery Co Ltd
Original Assignee
Hitachi Construction Machinery Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP3606394A external-priority patent/JPH07243222A/ja
Priority claimed from JP03606294A external-priority patent/JP3304186B2/ja
Application filed by Hitachi Construction Machinery Co Ltd filed Critical Hitachi Construction Machinery Co Ltd
Priority to EP98122113A priority Critical patent/EP0900886B1/de
Publication of EP0671511A2 publication Critical patent/EP0671511A2/de
Publication of EP0671511A3 publication Critical patent/EP0671511A3/de
Application granted granted Critical
Publication of EP0671511B1 publication Critical patent/EP0671511B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/30—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with a dipper-arm pivoted on a cantilever beam, i.e. boom
    • E02F3/32—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with a dipper-arm pivoted on a cantilever beam, i.e. boom working downwardly and towards the machine, e.g. with backhoes
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/30—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with a dipper-arm pivoted on a cantilever beam, i.e. boom
    • E02F3/301—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with a dipper-arm pivoted on a cantilever beam, i.e. boom with more than two arms (boom included), e.g. two-part boom with additional dipper-arm
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/30—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with a dipper-arm pivoted on a cantilever beam, i.e. boom
    • E02F3/302—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with a dipper-arm pivoted on a cantilever beam, i.e. boom with an additional link
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/30—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with a dipper-arm pivoted on a cantilever beam, i.e. boom
    • E02F3/32—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with a dipper-arm pivoted on a cantilever beam, i.e. boom working downwardly and towards the machine, e.g. with backhoes
    • E02F3/325—Backhoes of the miniature type
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/36—Component parts
    • E02F3/38—Cantilever beams, i.e. booms;, e.g. manufacturing processes, forms, geometry or materials used for booms; Dipper-arms, e.g. manufacturing processes, forms, geometry or materials used for dipper-arms; Bucket-arms
    • E02F3/382—Connections to the frame; Supports for booms or arms
    • E02F3/384—Connections to the frame; Supports for booms or arms the boom being pivotable relative to the frame about a vertical axis
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/2025—Particular purposes of control systems not otherwise provided for
    • E02F9/2033—Limiting the movement of frames or implements, e.g. to avoid collision between implements and the cabin
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/30—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with a dipper-arm pivoted on a cantilever beam, i.e. boom
    • E02F3/307—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with a dipper-arm pivoted on a cantilever beam, i.e. boom the boom and the dipper-arm being connected so as to permit relative movement in more than one plane

Definitions

  • the present invention relates to a swing type excavator according to the pre-characterizing portion of claim 1.
  • Such an excavator is known from JP-U-2-84857.
  • an excavator which can realize the so-called undercarriage-width turn that not only an upper structure is turned generally within the width of an undercarriage, but also a front attachment, including a bucket, an arm and a boom, can be turned together generally within the undercarriage width while assuming a posture where the front attachment is folded above the upper structure (hereinafter referred to as a turning posture).
  • a front attachment including a bucket, an arm and a boom
  • Such an excavator is called a ultra-small turn hydraulic shovel or excavator.
  • the ultra-small turn hydraulic excavator can take any directions within a circle of which diameter is given by the undercarriage width, it can perform desired work in any narrow place so long as the place has a width enough to allow an excavator body to pass there. For example, when construction work is executed in one lane of a two-lane road, the work can be performed while traffic is blocked not in both lanes, but in only one lane, which results in a minimum extent of traffic restriction.
  • the offset type excavator is of a structure that a boom is divided into a lower boom and an upper boom, the upper boom being horizontally tiltable with respect to the lower boom, and a parallel link mechanism and a cylinder for driving the parallel link mechanism are disposed between the lower boom and the upper boom.
  • a parallel link mechanism and a cylinder for driving the parallel link mechanism are disposed between the lower boom and the upper boom.
  • an arm is translated with respect to the lower boom through an action of the parallel link mechanism.
  • the ditch can be dug in a desired position transversely of the excavator body within the undercarriage width with no need of turning the upper structure.
  • the swing type excavator is of a structure that a swing post being able to swing horizontally is disposed in a front central portion of an upper structure forwardly of a cab, and a front attachment is mounted to the swing post.
  • a side ditch digging can be performed by turning the upper structure and swinging the swing post so that the whole of the front attachment is swung in the horizontal direction.
  • a boom of the swing type excavator comprises a mono-boom bent at a certain angle for the purpose of deep digging.
  • a boom usually has the form bent at a certain angle. To realize a ultra-small turn of the excavator having such a boom, one end of the boom is required to be supported to a position near the longitudinal center of an upper structure.
  • the excavator employs the swing type in combination with the construction that one end of the boom is supported to a position near the longitudinal center of the upper structure, the boom would interfere with a cab and a front attachment could not be swung to the same side as the cab, when the front attachment is horizontally swung with respect to the upper structure in an attempt at work of side ditch digging. Accordingly, the offset type excavator in which the arm is horizontally tiltable with respect to the boom must have been practiced to prevent an interference between the front attachment and the cab.
  • Another ultra-small turn hydraulic excavator which has also been practiced employs, based on the above offset type, a boom provided between an upper boom and a lower boom with an additional mechanism which enables the upper boom to be also vertically tiltable with respect to the lower boom, an opening angle between the two booms being changed by action of a cross link (hereinafter referred to as second prior art).
  • JP-U-2-84857 discloses a swing type excavator in which a boom comprises a lower boom vertically tiltable with respect to a swing post, and an upper boom vertically tiltable with respect to the lower boom (hereinafter referred to as third prior art).
  • a boom comprises a lower boom vertically tiltable with respect to a swing post, and an upper boom vertically tiltable with respect to the lower boom (hereinafter referred to as third prior art).
  • an opening angle between the two booms is changed by action of a cross link depending on a tilt angle of the lower boom so that when the lower boom is maximally tilted up (i.e., erected), the upper boom is straightly extended in the direction of extension of the lower boom, and when the lower boom is maximally tilted down (i.e., flattened), the upper boom is bent at a proper angle with respect to the lower boom.
  • a swing post is disposed in a front central portion of an upper structure.
  • a horizontal pin as a coupling point between a boom and a swing post is positioned forwardly of a swing pin as the swing center of the swing post toward a front attachment (hereinafter referred to as fourth prior art).
  • EP 0 448 849 A1 discloses a shovel excavator having a lower travelling structure and an upper frame structure with a boom which is positioned laterally of a cab.
  • the boom comprises a first and a second arm which are tiltable with respect to each other by a piston-cylinder arrangement.
  • the first arm of the boom is hinged to a support structure which is not of the swing type.
  • the shovel excavator does not provide a swing post for horizontally swinging the boom with respect to the upper frame structure.
  • the offset type excavator has problems below because the arm and the bucket are offset parallel to the boom.
  • the foot end of the boom cannot be supported to a position near the longitudinal center of the upper structure, and hence the excavator cannot be constructed in such a manner as enabling the whole of the front attachment to turn within the undercarriage width, as described before.
  • the foot end of the boom is supported by the swing post disposed substantially centrally in front of the cab, and a mono-boom vertically bent at a certain angle is employed as the boom.
  • the bent angle of the boom is set so as to enable deep digging when the boom is maximally tilted down, a part of the front attachment would project out of the undercarriage width upon the upper structure being turned even in a posture where the boom is maximally tilted up.
  • the swing post is disposed substantially centrally in front of the cab, the cab has to be shifted rearwardly on the narrow upper structure in order that the boom has a large tilt angle when it is maximally tilted up. This implies a difficulty in designing layout of the cab.
  • the third prior art since the opening angle between the lower boom and the upper boom is changed by action of the cross link depending on a tilt angle of the lower boom, the upper boom is bent with respect to the lower boom so as to enable deep digging when the lower boom is maximally tilted down, and the upper boom is straightly extended with respect to the lower boom when the lower boom is maximally tilted up, enabling the bucket to be raised to a higher level.
  • the swing post is disposed in the front central portion of the upper structure as with general swing type excavators, the lower boom would hit against the cab if the lower boom is attempted to tilt rearwardly beyond its vertical posture.
  • the maximum tilt-up angle of the lower boom cannot be set to a large value. This results in a limitation in reducing a minimum turn radius of the front attachment given when the lower boom is maximally tilted up.
  • the third prior art also has similar problems to those in the above swing type excavator having the mono-boom.
  • the object of the present invention is to provide a swing type excavator which can realize the undercarriage-width turn with a simple construction without using a complex link mechanism, i.e., without so increasing weight of a front attachment, and can easily avoid an interference between the front attachment and a cab when the front attachment is swung.
  • the opening angle adjustment means is set to change the opening angle between the lower boom and the upper boom such that the opening angle is increased as the lower boom is tilted up.
  • the opening angle adjustment means is set to change the opening angle between the lower boom and the upper boom such that the opening angle is increased as the lower boom is tilted up in a first region where the tilt angle of the lower boom is larger than a predetermined tilt angle, the opening angle is increased as the lower boom is tilted down in a second region where the tilt angle of the lower boom is smaller than the predetermined tilt angle, and the opening angle is minimized at the predetermined tilt angle.
  • the opening angle adjustment means is set such that the tilt angle of the lower boom in a maximum digging reach position of the front attachment is in the vicinity of the predetermined tilt angle.
  • the opening angle adjustment means is set to change the opening angle between the lower boom and the upper boom such that the opening angle takes a larger value when the tilt angle of the lower boom is in the vicinity of the maximum tilt-up angle of the lower boom than when the tilt angle of the lower boom is in the vicinity of a maximum tilt-down angle of the lower boom.
  • a coupling point between the lower boom and the swing post is positioned rearwardly of the swing center of the swing post away from the front attachment.
  • the opening angle adjustment means comprises a cross link having one end coupled to the swing post through a horizontal pin and the other end coupled to the upper boom through a horizontal pin such that the cross link intersects a line connecting the coupling point between the lower boom and the swing post and a coupling point between the lower boom and the upper boom.
  • a position of the coupling point between the cross link and the swing post is rearwardly or forwardly of a position of the coupling point between the lower boom and the swing post away from or toward the front attachment.
  • the opening angle adjustment means comprises a hydraulic cylinder having one end coupled to the swing post or the lower boom through a horizontal pin and the other end coupled to the upper boom through a horizontal pin, and means for controlling extension and contraction of the hydraulic cylinder such that the opening angle between the lower boom and the upper boom is changed depending on the vertical tilt angle of the lower boom.
  • the boom is divided into the lower boom and the upper boom, and the opening angle between the lower boom and the upper boom (hereinafter referred to as the boom-to-boom opening angle) is changed by the opening angle adjustment means depending on the vertical tilt angle of the lower boom so that the boom-to-boom opening angle is maximized in a turning posture where the lower boom is fully tilted up and the front attachment is folded.
  • the swing post is disposed on the upper structure in a position forwardly and laterally of the cab, allowing the lower boom to take an increased maximum tilt-up angle with no need of greatly changing layout, such as shifting the cab rearwardly, while preventing interference of the lower boom with the cab.
  • the minimum turn radius of the front attachment is so reduced as to enable the undercarriage-width turn.
  • a ultra-small turn excavator capable of realizing the undercarriage-width turn can be obtained by employing a simple structure of the swing type, without using a complex parallel link mechanism.
  • the swing post is only disposed in a position forwardly and laterally of the cab, there still exists a possibility that the bucket may hit against the cab when the boom is tilted up and the arm is folded in a condition where the swing post and the front attachment are swung perpendicularly to the cab on the same side.
  • the opening angle adjustment means which increases the boom-to-boom opening angle with tilting-up of the lower boom, the bucket passes above the cab, thus eliminating a possibility that the bucket may hit against the cab.
  • the opening angle adjustment means is set to increase the boom-to-boom opening angle as the lower boom is tilted up, the boom-to-boom opening angle in the maximum tilt-up position of the lower boom is so enlarged that the front attachment can take the turning posture narrower than the undercarriage width.
  • the opening angle adjustment means is set to change the boom-to-boom opening angle such that it is increased as the lower boom is tilted up in a first region where the tilt angle of the lower boom is larger than a predetermined tilt angle, and it is increased as the lower boom is tilted down in a second region where the tilt angle of the lower boom is smaller than the predetermined tilt angle. Therefore, in the first region, the boom-to-boom opening angle in the maximum tilt-up position of the lower boom is enlarged, enabling the front attachment to take the turning posture narrower than the undercarriage width and, in the second region, the boom-to-boom opening angle in the maximum tilt-down position of the lower boom is enlarged, enabling the bucket to be moved to a deeper position for deep digging.
  • the boom-to-boom opening angle is minimized at the predetermined tilt angle. Therefore, when the tilt angle of the lower boom in the maximum digging reach position of the front attachment is set to be in the vicinity of the predetermined tilt angle, the boom-to-boom opening angle in the maximum digging reach position is reduced and the maximum digging reach length from the turn center to a tip end of the bucket is shortened. As a result, the tipping moment in the maximum digging reach position is reduced to increase stability of the excavator.
  • the maximum digging reach length is most shortened and the effect of increasing stability of the excavator is maximized.
  • the opening angle adjustment means is set to change the boom-to-boom opening angle such that it takes a larger value when the tilt angle of the lower boom is in the vicinity of the maximum tilt-up angle thereof than when the tilt angle of the lower boom is in the vicinity of a maximum tilt-down angle thereof.
  • This feature also enables, as with the above case, the front attachment to take the turning posture narrower than the undercarriage width in a condition where the lower boom is fully tilted up, and the bucket to be moved to a deeper position for deep digging in a condition where the lower boom is fully tilted down.
  • the vertical tilt point of the lower boom and hence the front attachment comes closer to the turn center of the upper structure. Accordingly, the minimum turn radius is further reduced and, corresponding to this reduction, an increase in the boom-to-boom opening angle necessary for keeping the front attachment within the undercarriage width is reduced and the burden imposed on the opening angle adjustment means is diminished. Moreover, as a result of the vertical tilt center of the front attachment coming closer to the turn center of the upper structure, the maximum digging reach length from the turn center to the tip end of the bucket is shortened and hence the tipping moment in the maximum digging reach position is further reduced to ensure higher stability of the excavator. On the other hand, since the swing center of the swing post is not changed, the side ditch distance (i.e., the distance from an outer lateral surface of the undercarriage to an outer wall surface of the side ditch) is not sacrificed.
  • the opening angle adjustment means comprises a cross link having one end coupled to the swing post through a horizontal pin and the other end coupled to the upper boom through a horizontal pin, the cross link being arranged to intersect a line connecting the coupling point between the lower boom and the swing post and the coupling point between the lower boom and the upper boom, the boom-to-boom opening angle in the maximum tilt-up position of the lower boom is so enlarged that the front attachment can take the turning posture narrower than the undercarriage width in that position of the lower boom.
  • the boom-to-boom opening angle in the maximum digging reach position is reduced and the maximum digging reach length from the turn center to the tip end of the bucket is shortened. Furthermore, the boom-to-boom opening angle in the maximum tilt-down position of the lower boom is increased to enable deep digging.
  • the position of the coupling point between the cross link and the swing post is set to be forwardly of the position of the coupling point between the lower boom and the swing post toward the front attachment.
  • the opening angle adjustment means comprises a hydraulic cylinder having one end coupled to the swing post or the lower boom through a horizontal pin and the other end coupled to the upper boom through a horizontal pin, and means for controlling extension and contraction of the hydraulic cylinder such that the opening angle between the lower boom and the upper boom is changed depending on the vertical tilt angle of the lower boom, the boom-to-boom opening angle can be changed depending on the vertical tilt angle of the lower boom. Additionally, in this case, the extension and contraction of the hydraulic cylinder can be changed at any desired rate, and hence the boom-to-boom opening angle can also be changed at any desired rate.
  • undercarriage width generally within the undercarriage width
  • the upper structure including the front attachment turns “within the undercarriage width” in a practical sense and, though depending on the machine size, it is allowed for the turning components to protrude from the undercarriage width (i.e., side ends of the undercarriage) on the order of several tens millimeters during use.
  • the coupling point between the boom and the swing post is positioned rearwardly of the swing center of the swing post away from the front attachment. Therefore, the vertical tilt point of the boom and hence the front attachment comes closer to the turn center of the upper structure, and the minimum turn radius in the turning posture is reduced. Also, since the position of the swing post (i.e., the swing center) with respect to the upper structure is not required to be changed, the front attachment is not shifted toward the turn center of the upper structure when a side ditch is dug by turning the upper structure and swinging the whole of the front attachment in the opposite direction to the upper structure, and hence the same side ditch distance as in the prior art is ensured. Further, since the position of the swing post is not changed, the maximum tilt-down angle of the boom in the deep digging posture is also not changed and the same maximum digging depth as in the prior art is obtained.
  • the maximum digging reach length from the turn center to the tip end of the bucket is shortened and hence the tipping moment in the maximum digging reach position is reduced to increase stability of the excavator.
  • Fig. 1 is a side view showing a construction of a swing type excavator according to one embodiment of the present invention.
  • Fig. 2 is a plan view of the excavator of Fig. 1.
  • Fig. 3 is a view for explaining operation of a front attachment in the excavator of Figs. 1 and 2, in which a cab is omitted and only its outer contour is indicated by two-dot-chain lines for the sake of simplicity.
  • Fig. 4 is a plan view of the excavator in a turning posture in Fig. 3.
  • Fig. 5A is an enlarged view of a swing post in the excavator of Figs. 1 and 2
  • Fig. 5B is a view showing a comparative example in which a horizontal pin is positioned forwardly of a swing pin toward the front attachment.
  • Fig. 6 is a view for comparatively showing motions of the front attachments mounted to the respective swing posts in Figs. 5A and 5B, the view illustrating the cab in the simplified form as with Fig. 3.
  • Figs. 7A and 7B are plan views showing a condition of side ditch digging in which; Fig. 7A represents the case of the embodiment shown in Fig. 5A and Fig. 7B represents the case of the comparative example shown in Fig. 5B.
  • Fig. 8 is a side view showing a construction and operation of a swing type excavator according to another embodiment of the present invention, the view illustrating the cab in the simplified form as with Fig. 3.
  • Fig. 9 is a side view showing a construction and operation of a swing type excavator according to still another embodiment of the present invention, the view illustrating the cab in the simplified form as with Fig. 3.
  • Fig. 10 is a block diagram of principal parts of a hydraulic circuit for an upper boom cylinder in Fig. 9.
  • Fig. 11 is a block diagram showing a configuration of a controller in Fig. 10.
  • Fig. 12 is a flowchart for control of an upper boom cylinder to be performed in the controller of Fig. 10.
  • Fig. 13 is a side view showing a modification of the excavator in Fig. 9 wherein an upper boom cylinder is coupled between a lower boom and an upper boom, the view illustrating the cab in the simplified form as with Fig. 3.
  • Fig. 14 is a view, similar to Fig. 1, showing an embodiment in which the present invention is applied to excavator having a canopy type cab.
  • Fig. 15 is a side view showing a construction of a swing type excavator according to a related art.
  • Fig. 16A is an enlarged view of a swing post in the excavator of Fig. 15, and Fig. 16B is a view showing a comparative example in which a horizontal pin is positioned forwardly of a swing pin toward a front attachment.
  • Fig. 17 is a view of a related art for comparatively showing motions of the front attachments mounted to the respective swing posts in Figs. 16A and 16B, in which a cab is omitted and only its outer contour is indicated by two-dot-chain lines for the sake of simplicity.
  • Figs. 18A and 18B are plan views showing a condition of side ditch digging in which; Fig. 18A represents the case of the embodiment shown in Fig. 16A and Fig. 18B represents the case of the comparative example shown in Fig. 16B.
  • the excavator of this embodiment is a ultra-small turn hydraulic shovel which can realize an undercarriage-width turn.
  • an upper structure 11 is mounted on an undercarriage 10 which travels to move an excavator body, and a cab 12 is mounted on the upper structure 11 in its one side.
  • a swing post 13 is attached by a swing pin 30, as a vertical pin, to the upper structure 11 at a position forwardly and laterally of the cab 12.
  • the swing post 13 is swingable in the horizontal direction about the swing pin 30.
  • a seat, various control levers and so on are installed in the cab 12.
  • the upper structure 11 has such a size that it can swing generally within a width of the undercarriage 10, and is operated by a turning mechanism (not shown) so as to turn horizontally.
  • a turning mechanism not shown
  • all kinds of equipment necessary for a typical hydraulic shovel or excavator e.g., hydraulic devices such as hydraulic pumps and valves for driving a boom cylinder 16, an arm cylinder 18, a bucket cylinder 20 and a swing cylinder 23, which will be described later, an engine, etc. are also mounted on the upper structure 11.
  • the boom is divided into two parts, i.e., the lower boom 14 and the upper boom 17.
  • the lower boom 14 has a foot end coupled to the swing post 13 by a horizontal pin 31, and a distal end coupled to the upper boom 17 by a horizontal pin 32.
  • the boom cylinder 16 has a bottom-side end coupled to the swing post 13 by a horizontal pin 16A, and a rod distal end coupled to the lower boom 14 by a horizontal pin 16B, thereby tilting the lower boom 14 vertically upon its extension and contraction.
  • the boom cylinder 16 serve as a power source to tilt the lower boom 14.
  • the upper boom 17 has a bottom end coupled to the lower boom 14 by the horizontal pin 32 as mentioned above, and a distal end coupled to the arm 19 by a horizontal pin 33. Additionally, the cross link 15, described later, is coupled to the upper boom 17 by a horizontal pin 34.
  • a tilt angle of the lower boom 14 is maximized in the upward direction when the boom cylinder 16 is extended to a maximum, and is maximized in the downward direction when the boom cylinder 16 is contracted to a minimum. Also, as the tilt angle in the upward direction is increased, the lower boom 14 is gradually inclined rearwardly beyond its vertical posture.
  • the maximum tilt-up angle of the lower boom 14 has been limited to such an extent that the lower boom 14 will not be inclined rearwardly up to a position of the cab.
  • the maximum tilt-up angle of the lower boom 14 given when the boom cylinder 16 is maximally extended is set in this embodiment so that the lower boom 14 may be inclined up to a position where it interferes with the cab 12 in the prior art, i.e., the lower boom 14 may be inclined rearwardly up to a position exceeding a line laterally extended from the cab 12. That setting is realized by properly designing a maximum stroke of the boom cylinder 16 given when it is maximally extended, and its mount relation with respect to the swing post 13.
  • the horizontal pin 31 as a coupling point between the lower boom 14 and the swing post 13 is positioned rearwardly of the swing pin 30 as the swing center of the swing post 13 away from the front attachment 1.
  • the cross link 15 is a member constituting an opening angle adjustment means, and has one end coupled to the swing post 13 by a horizontal pin 35, and the other end coupled to the upper boom 17 by the horizontal pin 34.
  • the horizontal pin 35 at one end of the cross link 15 is positioned rearwardly of the horizontal pin 31 at the foot end of the lower boom 14 away from the front attachment 1.
  • the cross link 15 intersects a straight line connecting the horizontal pin 32 by which the upper boom 17 and the lower boom 14 are coupled to each other and the horizontal pin 31 by which the lower boom 14 and the swing post 13 are coupled to each other.
  • the cross link 15 serves to, as described later in detail, change an opening angle between the upper boom 17 and the lower boom 14 to be maximized when the lower boom 14 is maximally tilted up such that the lower boom 14 is inclined rearwardly beyond the line laterally extended from the cab 12. That maximum opening angle is set so as to provide the minimum turn radius of the front attachment 1 which is generally equal to or smaller than the width of the undercarriage 10 on condition that the lower boom 14 is inclined rearwardly beyond the line laterally extended from the cab 12.
  • the arm 19 is vertically tiltably coupled to the distal end of the upper boom 17 by the horizontal pin 33 as described above, and the bucket 22 is vertically tiltably coupled to a distal end of the arm 19 through bucket links 21.
  • the arm cylinder 18 is attached between the upper boom 17 and the arm 19 by horizontal pins 36, 37. An opening angle between the arm 19 and the upper boom 17 is changed upon the arm cylinder 18 being extended and contracted.
  • the bucket cylinder 20 is attached between the arm 19 and the bucket links 21 by horizontal pins 38, 39.
  • the bucket links 21 are moved with extension and contraction of the bucket cylinder 20, whereupon the bucket 22 is angularly moved about its coupling point to the arm 19 to thereby dig earth and sand, etc.
  • the arm cylinder 18 and the bucket cylinder 20 serve as power sources to angularly move the arm 19 and the bucket 22, respectively.
  • the swing cylinder 23 has a rod distal end coupled to the swing post 13 by a vertical pin 23a, and a bottom-side end coupled to a predetermined position on the upper structure 11 by a vertical pin 23b.
  • the swing cylinder 23 is extended and contracted as indicated by broken lines in Fig. 23, the swing post 13 is swung correspondingly as indicated by broken lines, and the front attachment 1 is also swung with respect to the upper structure 11 (see Fig. 2).
  • the upper structure 11 is turned and the swing cylinder 23 is selectively extended or contracted, thereby swinging the swing post 13 and hence the front attachment 1 in the opposite direction to the upper structure 11, as with conventional swing type excavators.
  • the horizontal pin 32 at the distal end of the lower boom 14 moves along a path A which is a circle (indicated by one-dot-chain line in Fig. 3) with the horizontal pin 31 at the foot end of the lower boom 14 as the center, and the horizontal pin 34 at the distal end of the cross link 15 moves along a path B which is a circle (indicated by two-dot-chain line in Fig. 3) with the horizontal pin 35 at one end of the cross link 15 as the center.
  • a path C of the horizontal pin 33 coupling the upper boom 17 and the arm 19 is also shown in Fig. 3.
  • the cross link 15 is designed such that the cross link 15 intersects the straight line connecting the horizontal pin 32 and the horizontal pin 31 in the posture of Fig.
  • the boom-to-boom opening angle is increased as the lower boom 14 is tilted upwardly.
  • the boom-to-boom opening angle is increased as the lower boom 14 is tilted downwardly.
  • the boom-to-boom opening angle is minimized when the tilt angle of the lower boom 14 is a predetermined angle ⁇ from the horizontal direction, i.e., at the boundary between the first region and the second region.
  • the tilt angle of the lower boom 14 in a maximum digging reach position, where the front attachment 1 is maximally extended along the ground surface is in the vicinity of the predetermined angle ⁇ .
  • the boom-to-boom opening angle is increased by the action of the cross link 15 so that the lower boom 14 and the upper boom 17 are gradually angularly spaced above the upper structure 11.
  • the boom cylinder 16 is maximally extended to maximize the tilt-up angle of the lower boom 14
  • the boom-to-boom opening angle is also maximized by the action of the cross link 15.
  • the front attachment 1 is accommodated within the width of the undercarriage 10 by extending the arm cylinder 18 and the bucket cylinder 20 to such an extent that the arm 19 and the bucket 22 are folded to locate near the upper boom 17 as shown.
  • the tilt angle ⁇ of the lower boo 14 in the maximum digging reach position of the front attachment 1 is not coincident with the predetermined angle ⁇ where boom-to-boom the opening angle is minimized, these angles may be set to be substantially equal to each other. By so setting, the maximum digging reach length takes a minimum value and the effect of improving stability is maximized.
  • Fig. 5A is an enlarged view showing such an arrangement.
  • Fig. 5B is an enlarged view showing a comparative example in which a horizontal pin 31a as the coupling point between a lower boom 14a and a swing post 13a is positioned forwardly of a swing pin 30a as the swing center of the swing post 13a toward a front attachment.
  • the swing post 13a is disposed on the upper structure in the same position as the swing post 13. In both the cases of Figs.
  • the horizontal pins 16A, 16C coupling the bottom-side ends of the boom cylinders 16, 16a to the swing posts 13, 13a are positioned forwardly of the swing pins 30, 30a.
  • the coupling point between the boom and the swing post is positioned forwardly of the swing center of the swing post toward the front attachment.
  • Fig. 6 comparatively shows motions of the front attachments mounted to the swing posts in Figs. 5A and 5B.
  • solid lines represent the motion of the front attachment in this embodiment of Fig. 5A
  • two-dot-chain lines represent the motion of the front attachment in the comparative example of Fig. 5B.
  • Figs. 7A and 7B show the excavator in a condition of side ditch digging in which; Fig. 7A represents the case of this embodiment shown in Fig. 5A and Fig. 7B represents the case of the comparative example shown in Fig. 5B.
  • the upper structure 11 is turned 90° clockwise on the drawing and the front attachment is swung 90° counterclockwise on the drawing to dig a side ditch in a limit position maximally shifted in the direction of the undercarriage width.
  • Fig. 7B identical members to those in Fig. 7A are denoted by the same reference numerals.
  • the swing center of the swing post 13 i.e., the position of the swing pin
  • the side ditch distance ⁇ is the same in both the cases of Figs. 7A and 7B.
  • the side ditch can be dug in a position transversely spaced from the longitudinal center of the excavator body by a distance comparable to that achieved in the prior art, and hence the side ditch distance is not sacrificed.
  • the positional relationship between the horizontal pin 16A at the foot end of the boom cylinder 16 and the swing pin 30 is not limited to that shown in Figs. 5A and 5B, but may be optionally set.
  • the boom comprises the lower boom 14 and the upper boom 17, and the boom-to-boom opening angle is changed by the action of the cross link 15 depending on the tilt angle of the lower boom 14 so that the opening angle is maximized in the turning posture where the lower boom 14 is tilted up to a maximum.
  • the swing post 13 since the swing post 13 is disposed in a position forwardly and laterally of the cab 12, the lower boom can take an increased maximum tilt-up angle with no need of shifting the cab 12 rearwardly, while preventing interference of the lower boom 14 with the cab 12. Therefore, the minimum turn radius of the front attachment 1 is so reduced as to enable the undercarriage-width turn.
  • a ultra-small turn excavator capable of realizing the undercarriage-width turn can be obtained by employing a simple structure of the swing type, without using a complex parallel link mechanism.
  • the degree of freedom in designing layout of the cab 12 on the narrow upper structure 11 can be increased.
  • the cab 12 may be installed in a more forward position than usual. This is advantageous in that the engine size can be increased correspondingly, which provides a greater allowance in design of the upper structure.
  • the cross link 15 is provided in such a manner as to increase the opening angle between the upper boom 17 and the lower boom 14 with tilting-up of the lower boom 14, the bucket 22 passes above the cab 12 when the lower boom 14 is tilted up and the arm 19 is folded in the condition where the swing post 13 and the front attachment 1 are swung perpendicularly to the cab 12 on the same side. As a result, a possibility that the bucket 22 may hit against the cab 12 is eliminated.
  • the cross link 15 is arranged such that one end thereof is coupled to the swing post 13 through the horizontal pin 35, the distal end thereof is coupled to the upper boom 17 through the horizontal pin 32, and it intersects the straight line connecting the horizontal pin 32 and the horizontal pin 31, the boom-to-boom opening angle in the maximum tilt-up position of the lower boom 14 is so enlarged that the front attachment can take the turning posture narrower than the undercarriage width in that position of the lower boom.
  • the boom-to-boom opening angle is reduced in the maximum digging reach position where the lower boom 14 is tilted down, and the tipping moment in the maximum digging reach position is reduced to increase stability of the excavator. Additionally, in the deep digging posture where the lower boom 14 is further pivotally lowered, the boom-to-boom opening angle is increased so as to enable deep digging.
  • the coupling point between the lower boom 14 and the swing post 13 is positioned rearwardly of the swing center of the swing post 13 away from the front attachment 1, the minimum turn radius is further reduced and an increase in the boom-to-boom opening angle necessary for keeping the front attachment 1 within the undercarriage width is reduced correspondingly to diminish the burden imposed on the cross link 15. Also, the maximum digging reach length is shortened and the tipping moment in the maximum digging reach position is further reduced to ensure higher stability of the excavator. Moreover, since the swing center of the swing post 13 is not changed, the side ditch distance is not sacrificed. Additionally, when loading dug earth and sand, etc. on a dump track or the like from the bucket 22, the earth and sand, etc. can be more easily loaded because of an increased space left open in front of the lower boom.
  • this embodiment of the swing type does not employ a heavy mechanism required for the offset type, the weight of the front attachment is reduced and the stability is increased. Also, since the counterweight can be made smaller correspondingly, it is possible to reduce the total weight of the excavator body and hence a transportation cost. The reduced weight of the excavator body results in other advantages of reducing a necessary engine output, cutting down a manufacture cost and a running cost, and improving fuel economy.
  • this embodiment is not of the offset type, the number of connection points where vertical pins are used is reduced, whereby the front attachment is not subject to such restrictions as imposed on conventional offset type excavators and application fields are widened. Additionally, since there is no fear of interference between a lower portion of the parallel link mechanism and the ground surface during side ditch digging, the digging depth can be increased as compared with standard type excavators. As a result of using no complex parallel link mechanism, the manufacture cost is reduced and maintenance work is less frequently required.
  • this embodiment is not of the offset type, there is no possibility that the front attachment 1 may badly interfere with the cab 12. Only when the front attachment 1 is swung to the side opposite to the cab 12 and the lower boom 14 is tilted upwardly, there is a possibility that the front attachment 1 slightly interferes with the cab 12, but an interference preventing area can be easily calculated just by detecting a vertical tilt angle and a swing angle of the lower boom 14. Unlike the conventional offset type excavators, therefore, an inexpensive and highly reliable interference preventing device can be realized with no need of detecting angles of all components of the front attachment in the ultra-small turn excavator.
  • a horizontal pin 35A at one end of a cross link 15A is positioned rearwardly of a horizontal pin 31A at a foot end of a lower boom 14A and, in the posture shown in Fig. 8, the cross link 15A intersects a straight line connecting a horizontal pin 32A by which the upper boom 17 and the lower boom 14A are coupled to each other and the horizontal pin 31A at which the lower boom 14 and the swing post 13A are coupled to each other.
  • the horizontal pin 32A at the distal end of the lower boom 14A moves along a path which is a circle (indicated by one-dot-chain line in Fig. 8) with the horizontal pin 31A as the center
  • the horizontal pin 34A at the distal end of the cross link 15A moves along a path which is a circle (indicated by two-dot-chain line in Fig. 8) with the horizontal pin 35A as the center.
  • the path of the horizontal pin 32A at the distal end of the lower boom 14A is overlapped with the path of the horizontal pin 34A at the distal end of the cross link 15A as shown in Fig. 8.
  • Fig. 8 As with the embodiment of Fig.
  • the boom-to-boom opening angle is gradually increased by the action of the cross link 15A and, when it is pivotally lowered from the turning position, the boom-to-boom opening angle is gradually reduced by the action of the cross link 15.
  • the opening angle ⁇ in the turning posture, the opening angle ⁇ in the maximum digging reach position, and the opening angle ⁇ in the deep digging posture are related to each other as follows: ⁇ > ⁇ > ⁇
  • the boom-to-boom opening angle is gradually reduced and, in the maximum digging reach position, the maximum digging reach length from the turn center to the tip end of the bucket 22 is shortened. Therefore, the tipping moment in the maximum digging reach position is reduced to increase stability of the excavator.
  • the magnitude relationship among ⁇ , ⁇ and ⁇ may be optionally set to prolong the maximum digging reach length, for example, by adjusting the position of the horizontal pin 35 of the cross link 15 and the length of the cross link 15.
  • the maximum digging reach length is shortened and the tipping moment is reduced to increase stability of the excavator like the above embodiment.
  • an upper boom cylinder 40 is employed as opening angle adjustment means instead of the cross link in Figs. 1 and 8.
  • the upper boom cylinder 40 is coupled between the swing post 13 and the upper boom 17 to generate force, when extended and contracted, for changing the opening angle between the upper boom 17 and the lower boom 14 (hereinafter referred to as the boom-to-boom opening angle).
  • the remaining construction is the same as in Figs. 1 and 8.
  • Fig. 10 is a block diagram of principal parts of a hydraulic circuit as means for controlling extension and contraction of the upper boom cylinder 40 in this embodiment.
  • a sensor 41 detects an elevation angle (vertical tilt angle) ⁇ of the lower boom
  • a sensor 42 detects a boom-to-boom opening angle ⁇ .
  • a controller 43 receives the angles ⁇ and ⁇ from the sensors 41 and 42, respectively, and applies to an amplifier 44 a voltage signal 43a corresponding to a flow rate supplied to the upper boom cylinder 40.
  • the amplifier 44 converts the voltage signal 43a into a current signal 44a, and the shift position of a directional control valve 45 is determined by the current signal 44a.
  • a hydraulic fluid delivered under pressure from a reservoir 46 by a hydraulic pump 47 is supplied at a certain rate to a rod-side port 40a or a bottom-side port 40b of the upper boom cylinder 40, thereby contracting or extending the upper boom cylinder 40.
  • a certain back pressure is applied to the circuit by a back pressure valve 48.
  • the controller 43 comprises an arithmetic unit 43A, a first memory 43B and a second memory 43C.
  • the first memory 43B stores the value of a boom-to-boom opening angle ⁇ 0 at the start of work
  • the second memory 43C is a function memory for storing a function table which represents the relationship between the angles ⁇ and ⁇ .
  • the detected angles ⁇ and ⁇ are input to the arithmetic unit 43A which calculates the voltage signal 43a corresponding to a flow rate supplied to the upper boom cylinder 40 while transferring data with respect to the first memory 43B and the second memory 43C.
  • step S1 an initial value of the elevation angle of the lower boom 14 prior to starting to operate the lower boom 14 is input and stored as ⁇ 0 in the first memory 43B beforehand. Then, it is determined in step S2 whether the time ⁇ t has elapsed or not after the start of operation. If ⁇ t has elapsed, the control flow goes to next step S3.
  • step S3 the elevation angle ⁇ of the lower boom 14 and the boom-to-boom opening angle ⁇ are detected by the sensors 41 and 42, respectively, and the arithmetic unit 43A reads both the angles. Then, in step S4, the arithmetic unit 43A reads the previous elevation angle ⁇ 0 of the lower boom 14 (before the time ⁇ t) from the first memory 43B. Subsequently, in step S5, an elevation angle (hereinafter denoted by [ ⁇ ]) after ⁇ t from the current time is calculated.
  • [ ⁇ ] 2 ⁇ - ⁇ 0
  • step S6 the arithmetic unit 43A reads [ ⁇ ] corresponding to the above [ ⁇ ], i.e., a boom-to-boom opening angle after ⁇ t from the current time, from the function table in the second memory 43C.
  • step S7 ⁇ 0 in the first memory 43B is replaced by ⁇ which is stored as new ⁇ 0 .
  • an extending or contracting speed of the upper boom cylinder 40 is calculated from [ ⁇ *] by utilizing a geometrical relation formula.
  • This geometrical relation formula is uniquely determined by the lengths and positions of the upper boom cylinder 40 and the lower boom 14, the coupling positions of the upper boom cylinder 40 and the lower boom 14 to the swing post 13, etc., and is stored in the arithmetic unit 43A.
  • a flow rate of the hydraulic fluid to be supplied to the upper boom cylinder 40 is calculated from the extending or contracting speed of the upper boom cylinder 40, followed by outputting the calculated result (i.e., the voltage signal 43a) to the amplifier 44 in step S11. It is then determined in step S12 whether the operation is to be completed or not. If so, the control flow is ended, but if not so, it is returned to step S1 to repeat the same procedures as described above.
  • the boom-to-boom opening angle is changed depending on the vertical tilt angle of the lower boom 14 by means of the upper boom cylinder 40, the controller 43 for controlling extension and contraction of the cylinder 40, and so on. Additionally, the extension and contraction of the upper boom cylinder 40 can be changed at any desired rate, and hence the boom-to-boom opening angle can also be changed at any desired rate.
  • an upper boom cylinder 50 may be coupled between the lower boom 14 and the upper boom 17 as shown in Fig. 13.
  • This modification can also provide similar advantages. Note that, in Fig. 13, identical members to those in Fig. 9 are denoted by the same reference numerals.
  • Fig. 14 shows such an embodiment in which a cab 12A is of the canopy type having only a roof 12B and being open to both sides.
  • a seat, various control levers and so on are similarly installed in a space below the roof 12A.
  • the excavator of Fig. 14 the remaining construction is the same as in the embodiment of Fig. 1. This modification can also provide similar advantages to those in the embodiment of Fig. 1.
  • the swing post 13 is disposed on the upper structure 11 in a position forwardly and laterally of the cab 12. This, however, is only illustrative and the arrangement may be modified such that the right front corner of the cab is cut-away so as to provide a space for accommodating the swing post 13.
  • the present invention can be applied also to such a modification, without impairing the advantages described before.
  • the excavator of this embodiment is a hydraulic shovel which can realize the ultra-small turn.
  • the excavator of this embodiment comprises an undercarriage 110 which travels to move an excavator body, and an upper structure 111 which is mounted on the undercarriage 110, with a closed type cab 112 mounted on the upper structure 111.
  • a swing post 113 is attached by a swing pin 130, as a vertical pin, to the upper structure 111 at a central position forwardly of the cab 112 in a horizontally swingable manner.
  • a front attachment 101 including a bucket 122, an arm 119 and a boom 114, is mounted to the swing post 113.
  • a blade 102 is provided so as to project forwardly of the undercarriage 110.
  • the cab 112 may be of the canopy type having only a roof. As well known, a driving seat, various control levers and so on are installed in the cab 112.
  • the upper structure 111 is able to turn horizontally on the undercarriage 110 by a turning mechanism (not shown).
  • a turning mechanism not shown.
  • all kinds of equipment necessary for a typical hydraulic shovel or excavator e.g., hydraulic devices such as hydraulic pumps and valves for driving a boom cylinder 116, an arm cylinder 118, a bucket cylinder 120 and a swing cylinder 123, which will be described later, an engine, etc. are also mounted on the upper structure 111.
  • the boom 114 is a mono-boom vertically bent at a certain angle, and has a foot end coupled to the swing post 113 by a horizontal pin 131. Also, the boom cylinder 116 has a bottom-side end coupled to the swing post 113 by a horizontal pin 116A, and a rod-side end coupled by a horizontal pin 116B to a bracket 114A which is fixed to an inner bent portion of the boom 14, thereby tilting the lower boom 114 vertically upon its extension and contraction. Thus, the boom cylinder 116 serve as a power source to tilt the boom 114.
  • the arm 119 is vertically tiltably coupled to a distal end of the boom 114 by a horizontal pin 133
  • the bucket 122 is vertically tiltably coupled to a distal end of the arm 119 through bucket links 121.
  • the arm cylinder 118 is attached between a bracket 114B fixed to an outer bent portion of the boom 114 and the arm 119 by horizontal pins 136, 137. An angle formed between the arm 119 and the boom 114 is changed upon the arm cylinder 118 being extended and contracted.
  • the bucket cylinder 120 is attached between the arm 119 and the bucket links 121 by horizontal pins 138, 139.
  • the bucket links 121 are moved with extension and contraction of the bucket cylinder 120, whereupon the bucket 122 is angularly moved about its coupling point to the arm 119 to thereby dig earth and sand, etc.
  • the arm cylinder 118 and the bucket cylinder 120 serve as power sources to angularly move the arm 119 and the bucket 122, respectively.
  • the horizontal pin 131 as a coupling point between the boom 114 and the swing post 113 is positioned rearwardly of the swing pin 130 as the swing center of the swing post 113 away from the front attachment 101.
  • the swing cylinder 123 has a rod-side end coupled to the swing post 113 by a vertical pin 123a, and a bottom-side end coupled to a predetermined position on the upper structure 111 by a vertical pin 123b (see Fig. 17).
  • the swing cylinder 123 is extended and contracted, the swing post 113 is swung correspondingly and the front attachment 101 is entirely swung in the horizontal direction with respect to the upper structure 111.
  • the upper structure 111 is turned and the swing cylinder 123 is extended or contracted depending on the direction of the turn, thereby swinging the swing post 113 and hence the front attachment 101 in the opposite direction to the upper structure 111.
  • Fig. 16A is an enlarged view showing the swing post 113 and thereabout in this embodiment
  • Fig. 16B is an enlarged view showing a swing post and thereabout in the prior art as a comparative example.
  • a horizontal pin 131a as the coupling point between a boom 114a and a swing post 113a is positioned forwardly of a swing pin 130a as the swing center of the swing post 113a toward a front attachment.
  • the horizontal pins 116A, 116C coupling the bottom-side ends of the boom cylinders 116, 116a to the swing posts 113, 113a are positioned forwardly of the swing pins 130, 130a.
  • Fig. 17 shows motions of the front attachments mounted to the swing posts in Figs. 16A and 16B.
  • solid lines represent the motion of the front attachment in this embodiment of Fig. 16A
  • two-dot-chain lines represent the motion of the front attachment in the comparative example of Fig. 16B.
  • the vertical tilt center of the boom 114 is positioned rearwardly of the swing center of the swing post 113 away from the front attachment 101
  • the vertical tilt center of the front attachment 101 comes closer to the turn center of the upper structure 111. Accordingly, the minimum turn radius of the front attachment in its turning posture is reduced in the amount corresponding to a shortened length a shown in Fig. 17.
  • the swing pin 130 of this embodiment is disposed on the upper structure in the same position as the swing pin 130a of the prior art. Therefore, even when the maximum tilt-down angle of the boom 114 in the deep digging posture is set to a value equal to that in the prior art, the boom cylinder 116 will not interfere with the blade 102 and, as seen from Fig. 17, the same maximum digging depth as in the prior art is obtained. Moreover, as a result of the vertical tilt center of the front attachment 101 coming closer to the turn center of the upper structure 111, the maximum digging reach length from the turn center to a tip end of the bucket 122 is reduced by a shortened length b shown in Fig. 17. Therefore, the tipping moment in the maximum digging reach position is reduced to increase stability of the excavator.
  • Figs. 18A and 18B show the excavator in a condition of side ditch digging in which; Fig. 18A represents the case of this embodiment shown in Fig. 16A and Fig. 18B represents the case of the comparative example shown in Fig. 16B.
  • the upper structure 111 is turned 90° clockwise on the drawing and the front attachment is swung 90° counterclockwise on the drawing to dig a side ditch in a limit position maximally shifted in the direction of the undercarriage width.
  • the vertical tilt center of the front attachment 101 is closer to the turn center of the upper structure 111 and, therefore, the vertical tilt center of the boom 114 (i.e., the position of the horizontal pin 131) is located on the drawing lower than in the comparative example of Fig. 18B.
  • the swing center of the swing post 113 i.e., the position of the swing pin
  • the front attachment itself does not move toward the turn center of the upper structure 111 in the condition of side ditch digging.
  • the side ditch distance ⁇ from an outer lateral surface of the undercarriage 110 to an outer wall surface of the side ditch is the same in both the cases of Figs. 18A and 18B.
  • the side ditch can be dug in a position transversely spaced from the longitudinal center of the excavator body by a distance comparable to that achieved in the prior art.
  • the positional relationship between the horizontal pin 116A at the foot end of the boom cylinder 116 and the swing pin 130 is not limited to that shown in Fig. 16, but may be optionally set.
  • the coupling point between the boom 114 and the swing post 113 is positioned rearwardly of the swing center of the swing post 113 away from the front attachment 101, the minimum turn radius in the turning posture can be so reduced as to realize the ultra-small turn. Also, since the position of the swing post 113 is not changed, the same side ditch distance as in the prior art is ensured and, in the deep digging posture, the same maximum digging depth as in the prior art is obtained.
  • the swing post 113 is disposed on the upper structure 111 in a central position forwardly of the cab 112 in the above embodiment, the present invention is not limited to such an arrangement.
  • the swing post may be disposed in a position forwardly and laterally of the cab, or in a space formed by cutting out a right-side corner forwardly of the cab.
  • the swing post may be disposed laterally of the cab.
  • similar advantages can be obtained by setting a position of the coupling point between the boom and the swing post in a like manner to that in the above embodiment.

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Claims (11)

  1. Schwenkbagger mit einem Fahrwerk (10), einem auf dem Fahrwerk (10) drehbar angeordneten oberen Aufbau (11), einer Kabine (12) und einem vorderen Anbau, der eine mit einem Arm (19) gekoppelte Schaufel (22) enthält, wobei der Arm (19) ferner mit einem auf dem oberen Aufbau (11) angeordneten Ausleger verbunden ist, wobei der obere Aufbau (11) eine Schwenksäule (13) aufweist, die den Ausleger des vorderen Anbaus derart abstützt, daß der gesamte vordere Anbau horizontal verschwenkbar ist, wobei der Ausleger des vorderen Anbaus einen durch einen Auslegerzylinder (16) bezüglich der Schwenksäule (13) vertikal schwenkbaren unteren Ausleger (14) und einen bezüglich des unteren Auslegers (14) vertikal schwenkbaren oberen Ausleger (17) enthält und wobei der vordere Anbau eine Öffnungswinkel-Einstelleinrichtung (15) zur Veränderung eines vertikalen Öffnungswinkels zwischen dem unteren Ausleger (14) und dem oberen Ausleger (17) in Abhängigkeit von einem vertikalen Schwenkwinkel des unteren Auslegers (14) enthält,
    dadurch gekennzeichnet,
    daß der obere Aufbau (11) eine derartige Größe aufweist, daß er im wesentlichen innerhalb einer Breite des Fahrwerks (10) drehbar ist;
    daß die Schwenksäule (13) an den oberen Aufbau (11) über einen Schwenkzapfen (30) in einer Position vor und seitlich der Kabine (12) angeordnet ist, so daß der untere Ausleger (14) nach hinten in eine Position über eine von einem vorderen Teil der Kabine (12) seitlich verlaufende Linie hinaus verschwenkt werden kann; und
    daß die Öffnungswinkel-Einstelleinrichtung (15) derart zur Einstellung des vertikalen Öffnungswinkels zwischen dem unteren Ausleger (14) und dem oberen Ausleger (17) ausgelegt ist, daß der vordere Anbau innerhalb der Breite des Fahrwerks (10) aufgenommen ist, wenn der untere Ausleger (14) in die Position über die von dem Kabinenvorderteil seitlich verlaufende Linie hinaus verschwenkt und der Arm (19) eingeklappt ist.
  2. Schwenkbagger nach Anspruch 1, bei dem die Öffnungswinkel-Einstelleinrichtung derart zur Veränderung des Öffnungswinkels zwischen dem unteren Ausleger (14) und dem oberen Ausleger (17) ausgebildet ist, daß der Öffnungswinkel beim Hochschwenken des unteren Auslegers (14) vergrößert wird.
  3. Schwenkbagger nach Anspruch 1, bei dem die Öffnungswinkel-Einstelleinrichtung derart zur Veränderung des Öffnungswinkels zwischen dem unteren Ausleger (14) und dem oberen Ausleger (17) ausgebildet ist, daß der Öffnungswinkel vergrößert wird, wenn der untere Ausleger (14) in einem ersten Bereich nach oben geschwenkt wird, in dem der Schwenkwinkel des unteren Auslegers (14) größer als ein vorbestimmter Schwenkwinkel ist, wobei der Öffnungswinkel vergrößert wird, wenn der untere Ausleger (14) in einem zweiten Bereich nach unten geschwenkt wird, in dem der Schwenkwinkel des unteren Auslegers (14) kleiner als der vorbestimmte Schwenkwinkel ist, und wobei der Öffnungswinkel bei diesem vorbestimmten Schwenkwinkel minimiert ist.
  4. Schwenkbagger nach Anspruch 3, bei dem die Öffnungswinkel-Einstelleinrichtung derart ausgelegt ist, daß sich der Schwenkwinkel des unteren Auslegers (14) in einer Stellung mit maximalem Baggerbereich des vorderen Aufbaus in der Nähe des vorbestimmten Schwenkwinkels befindet.
  5. Schwenkbagger nach Anspruch 1, bei dem die Öffnungswinkel-Einstelleinrichtung derart zur Veränderung des Öffnungswinkels zwischen dem unteren Ausleger (14) und dem oberen Ausleger (17) ausgelegt ist, daß der Öffnungswinkel einen größeren Wert einnimmt, wenn der Schwenkwinkel des unteren Auslegers (14) in der Nähe des maximalen Schwenkwinkels beim Hochschwenken des unteren Auslegers (14) als wenn der Schwenkwinkel des unteren Auslegers (14) in der Nähe eines maximalen Schwenkwinkels beim Herunterschwenken des unteren Auslegers (14) ist.
  6. Schwenkbagger nach Anspruch 1, bei dem ein Kopplungspunkt zwischen dem unteren Ausleger (14) und der Schwenksäule (13) hinter dem Schwenkpunkt der Schwenksäule (13) vom vorderen Anbau weg angeordnet ist.
  7. Schwenkbagger nach Anspruch 1, bei dem die Öffnungswinkel-Einstelleinrichtung eine Querverbindung (15) aufweist, deren eines Ende mit der Schwenksäule (13) über einen Horizontalbolzen und deren anderes Ende mit dem oberen Ausleger über einen Horizontalbolzen derart verbunden ist, daß die Querverbindung (15) eine Linie schneidet, die den Kopplungspunkt zwischen dem unteren Ausleger (14) und der Schwenksäule (13) und einen Kupplungspunkt zwischen dem unteren Ausleger (14) und dem oberen Ausleger (17) verbindet.
  8. Schwenkbagger nach Anspruch 7, bei dem eine Position des Kopplungspunkts zwischen der Querverbindung (15) und der Schwenksäule (13) hinter einer Position des Kopplungspunkts zwischen dem unteren Ausleger (14) und der Schwenksäule (13) von dem vorderen Anbau weg angeordnet ist.
  9. Schwenkbagger nach Anspruch 7, bei dem eine Position des Kopplungspunkts zwischen der Querverbindung (15) und der Schwenksäule (13) vor einer Position des Kopplungspunkts zwischen dem unteren Ausleger (14) und der Schwenksäule (13) zum vorderen Anbau hin angeordnet ist.
  10. Schwenkbagger nach Anspruch 1, bei dem die Öffnungswinkel-Einstelleinrichtung einen Hydraulikzylinder (16) mit einem über einen Horizontalbolzen mit der Schwenksäule (13) verbundenen einen Ende und einem über einen Horizontalbolzen mit dem oberen Ausleger (17) verbundenen anderen Ende und eine Einrichtung zur Steuerung der Ausfahr- und Einfahrbewegung des Hydraulikzylinders (16) derart aufweist, daß der Öffnungswinkel zwischen dem unteren Ausleger (14) und dem oberen Ausleger (17) in Abhängigkeit von dem vertikalen Schwenkwinkel des unteren Auslegers (14) verändert wird.
  11. Schwenkbagger nach Anspruch 1, bei dem die Öffnungswinkel-Einstelleinrichtung einen Hydraulikzylinder (18) mit einem über einen Horizontalbolzen mit dem unteren Ausleger (14) verbundenen einen Ende und einem mit dem oberen Ausleger (17) über einen Horizontalbolzen verbundenen anderen Ende und eine Einrichtung zur Steuerung der Ausfahr- und Einfahrbewegung des Hydraulikzylinders (18) derart aufweist, daß der Öffnungswinkel zwischen dem unteren Ausleger (14) und dem oberen Ausleger (17) in Abhängigkeit von dem vertikalen Schwenkwinkel des unteren Auslegers (14) verändert wird.
EP19950103250 1994-03-07 1995-03-07 Schwenkbagger Expired - Lifetime EP0671511B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP98122113A EP0900886B1 (de) 1994-03-07 1995-03-07 Schwenkbagger

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
JP36062/94 1994-03-07
JP36063/94 1994-03-07
JP3606394A JPH07243222A (ja) 1994-03-07 1994-03-07 スイング方式の掘削機
JP3606394 1994-03-07
JP3606294 1994-03-07
JP03606294A JP3304186B2 (ja) 1994-03-07 1994-03-07 スイング方式の掘削機

Related Child Applications (1)

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EP98122113A Division EP0900886B1 (de) 1994-03-07 1995-03-07 Schwenkbagger

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EP0671511A2 EP0671511A2 (de) 1995-09-13
EP0671511A3 EP0671511A3 (de) 1996-02-14
EP0671511B1 true EP0671511B1 (de) 2000-01-26

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EP19950103250 Expired - Lifetime EP0671511B1 (de) 1994-03-07 1995-03-07 Schwenkbagger

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Publication number Priority date Publication date Assignee Title
CN1078286C (zh) * 1996-01-31 2002-01-23 日立建机株式会社 挖掘机
JP3734189B2 (ja) * 1996-07-19 2006-01-11 株式会社小松製作所 ２ピースブーム型建設機械のストロークエンドショック低減装置
CN102720231B (zh) * 2012-06-13 2015-06-10 太原科技大学 单斗液压挖掘机反铲工作装置铰点的设计方法
CN103397671A (zh) * 2013-08-24 2013-11-20 安徽宏昌机电装备制造有限公司 矿用挖掘式装载机的挖掘装置
DE102013221302A1 (de) * 2013-10-21 2015-04-23 Mts Maschinentechnik Schrode Ag Baumaschine
CN106759575A (zh) * 2017-02-04 2017-05-31 柳州柳工挖掘机有限公司 挖掘机
CN108560624B (zh) * 2018-06-26 2023-07-04 江苏徐工工程机械研究院有限公司 挖掘臂及挖掘设备
CN108824513B (zh) * 2018-08-29 2024-01-30 四川畅安穿山甲科技有限公司 一种挖掘机动臂
WO2021137789A1 (en) * 2019-12-30 2021-07-08 Hi̇dromek-Hi̇droli̇k Ve Mekani̇k Maki̇na İmalat Sanayi̇ Ve Ti̇caret Anoni̇m Şi̇rketi̇ Hydraulic cylinder increasing the rotation angle of the attachment integrated to the construction machines
NL2024981B1 (en) * 2020-02-24 2021-10-14 Hudson I P B V Electric drive of mobile apparatus
CN111395420A (zh) * 2020-04-30 2020-07-10 长沙中联恒通机械有限公司 一种挖掘装置及工程车

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DE3245489A1 (de) * 1982-12-06 1984-06-14 O & K Orenstein & Koppel Ag, 1000 Berlin Ausleger einer baggerausruestung
FR2573183B1 (fr) * 1984-11-14 1987-02-13 Francais Ciments Generateur d'air chaud a combustibles solides a multiples usages notamment en cimenterie
JPS63272820A (ja) * 1987-05-01 1988-11-10 Mitsubishi Heavy Ind Ltd 掘削運搬車両
JPH0284857U (de) * 1988-12-16 1990-07-02
JP2685871B2 (ja) 1989-02-15 1997-12-03 日立建機株式会社 側溝掘フロントの油圧回路
JPH06104985B2 (ja) 1989-09-21 1994-12-21 株式会社クボタ バックホウの制御装置
EP0448849B1 (de) * 1990-03-27 1994-11-09 ATLAS WEYHAUSEN GmbH Ausleger für einen Löffelbagger od. dgl.
JPH0739965Y2 (ja) 1990-08-22 1995-09-13 株式会社神戸製鋼所 小型ショベルのスイング装置
JPH0547798U (ja) 1991-11-13 1993-06-25 石川島播磨重工業株式会社 炉における軸貫通部のシール構造
DE4139379A1 (de) * 1991-11-29 1993-06-24 Dfa Fertigungs Und Anlagenbau Arbeitsmaschine fuer abbruch-, lade- und grabearbeiten
JP2812417B2 (ja) * 1993-01-20 1998-10-22 ヤンマーディーゼル株式会社 旋回型掘削作業車

Also Published As

Publication number Publication date
EP0900886A3 (de) 2001-01-31
DE69533115D1 (de) 2004-07-08
DE69514699D1 (de) 2000-03-02
EP0900886A2 (de) 1999-03-10
EP0671511A2 (de) 1995-09-13
EP0900886B1 (de) 2004-06-02
EP0671511A3 (de) 1996-02-14
DE69514699T2 (de) 2000-05-31
DE69533115T2 (de) 2004-09-30

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