Suction nozzle

Abstract

The suction nozzle according to the present disclosure comprises: a suction nozzle housing having a suction space opened downward so as to suck dust on the floor; a driving unit for generating a driving force; a brush roller that is rotatably supported by the suction nozzle housing in a state in which the brush roller can be in contact with the floor surface, and that rotates on the basis of the driving force of the driving unit so as to generate a propulsive force for advancing the suction nozzle while sweeping dust on the floor surface; and a rear roller rotatably attached to the nozzle housing so as to roll on the ground on the rear side with respect to the brush roller when the nozzle advances. The brush roller and the rear roller support the suction nozzle housing in such a manner that the lower side surface of the suction nozzle housing is in a backward tilting posture that the lower side surface descends rearward.

Description

Technical Field

[0001] The invention relates to a nozzle for a suction type vacuum cleaner. Background Art

[0002] A suction type vacuum cleaner comprises: a suction source for generating a suction force; and a suction pipe having a flow path through which dust sucked by the suction force of the suction source flows. The user operates the suction pipe so that the distal end of the suction pipe approaches a desired position to suck the dust at that position. The flow path of the suction pipe is too narrow to suck in dust scattered over a wide area on the ground, and therefore, a suction nozzle that is larger than the width of the suction pipe is sometimes installed at the distal end of the suction pipe (see Patent Document 1).

[0003] The nozzle of Patent Document 1 comprises: a nozzle housing, which forms a suction space opening downward; and a plurality of rollers, which are arranged to support the nozzle housing at a position away from the ground and roll on the ground. The rollers include: a front roller arranged at the front side relative to the suction space; and a rear roller arranged at the rear side relative to the suction space. The front roller and the rear roller partially protrude from the lower side of the nozzle housing, and the protrusion amount of the front roller and the rear roller from the lower side of the nozzle housing is set in a manner that the lower side of the nozzle housing is parallel to the ground.

[0004] A brush roller configured to sweep dust on the floor is disposed in the suction space of the nozzle housing. In addition, a driving unit configured to drive the brush roller to rotate is disposed in the nozzle housing. The brush roller has a cylindrical roller body and a brush implanted in the roller body, wherein the brush roller is supported by the nozzle housing in such a manner that the brush protrudes downward from the suction space. When the driving unit rotates the brush roller, the brush of the brush roller rubs against the floor and can sweep dust on the floor. At this time, the driving force of the driving unit that rotates the brush roller becomes a propulsion force that moves the nozzle forward, thereby assisting the nozzle in moving forward.

[0005] When the suction nozzle of Patent Document 1 moves forward on a carpet laid on the ground, for example, the pile of the carpet may be caught by the front end of the suction nozzle housing. In this case, the suction nozzle housing may lose its substantially parallel posture with the ground, so the suction nozzle may be in a forward tilted posture with the rear roller suspended relative to the carpet, or, conversely, in a backward tilted posture with the front roller suspended relative to the carpet. If the suction nozzle is in such a forward tilted posture or backward tilted posture, the contact between the brush roller and the carpet will be weakened, and as a result, the propulsion force of the brush roller may also be weakened.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent document 1: Japanese Patent Publication No. 11-197062 Summary of the invention

[0009] An object of the present disclosure is to provide a suction nozzle that can move forward on the ground with a stable posture.

[0010] The nozzle involved in one aspect of the present disclosure can be used in a suction-type vacuum cleaner. The nozzle includes: a nozzle housing, which forms a suction space that opens downward so that dust on the ground can be sucked in; a driving unit that generates a driving force; a brush roller that is rotatably supported by the nozzle housing in a state in contact with the ground, and rotates based on the driving force of the driving unit, thereby sweeping the dust on the ground while generating a propulsion force to move the nozzle forward; and a rear roller that is rotatably mounted on the nozzle housing in a manner that rolls on the ground at the rear side relative to the brush roller when the nozzle moves forward. The brush roller and the rear roller support the nozzle housing in a manner that causes the lower side of the nozzle housing to be in a backward tilted posture that is downwardly descending.

[0011] The suction nozzle can move forward on the ground in a stable posture.

[0012] The objects, features and advantages of the present disclosure will become more apparent from the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a side view of the vacuum cleaner equipped with the suction nozzle of 1st Embodiment.

[0014] Figure 2 It is a three-dimensional diagram of the nozzle.

[0015] Figure 3 It is a bottom view of the nozzle.

[0016] Figure 4 It is a longitudinal sectional view of the suction nozzle.

[0017] Figure 5 It is an enlarged cross-sectional view of the periphery of the rear roller of the suction nozzle.

[0018] Figure 6 It is the bottom view of other nozzles.

[0019] Figure 7 It is the bottom view of other nozzles.

[0020] Figure 8 It is a perspective view of the suction nozzle of the second embodiment.

[0021] Fig. 9 It is an enlarged cross-sectional view of the periphery of the movable part of the suction nozzle.

[0022] Fig.10 It is a bottom view of the nozzle.

[0023] Fig.11 This is an enlarged bottom view of the periphery of the movable portion of the suction nozzle.

[0024] Fig.12 It is an enlarged perspective view of the periphery of the movable part of the suction nozzle.

[0025] Fig.13 It is a longitudinal sectional view of the suction nozzle of 3rd Embodiment.

[0026] Fig.14 It is a longitudinal sectional view of other suction nozzles.

[0027] Fig.15 It is a bottom view of the suction nozzle of the fourth embodiment. DETAILED DESCRIPTION

[0028] Hereinafter, the first to fourth embodiments of the suction nozzle will be described in detail with reference to the accompanying drawings, but unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters or repeated descriptions of substantially the same structures may be omitted. This is to avoid the following description from becoming unnecessarily lengthy so that it is easy for those skilled in the art to understand. In addition, the drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0029] <First embodiment>

[0030] Figure 1 1 is a schematic side view of a suction-type vacuum cleaner 200 including a suction nozzle 100. Figure 1 The vacuum cleaner 200 will be described.

[0031] (Overall structure of the vacuum cleaner)

[0032] The vacuum cleaner 200 includes: a vacuum cleaner body 210, which has a suction source 211 for generating suction force for sucking dust and a battery 212 for supplying power to the suction source 211; and a suction pipe 220, which is extended downward from the vacuum cleaner body 210. The suction source 211 may include: a motor; and a rotating blade that rotates based on the motor. In order to allow the suction force of the suction source 211 to act on a wide area on the ground, a suction nozzle 100 is installed at the lower end of the suction pipe 220.

[0033] In the vacuum cleaner body 210, the battery 212 is arranged at the front side relative to the suction source 211. A stick-shaped gripping portion 230 having a thickness that allows the user to grip is extended upward from the upper side of the front side portion of the vacuum cleaner body 210 where the battery 212 is arranged. An operating portion 231 operated by the user to start or stop the suction source 211 is arranged on the front side of the gripping portion 230.

[0034] The suction pipe 220 has three tubes and forms a flow path for the dust and air sucked up by the suction force of the suction source 211 to flow. One of these tubes is a base end tube portion 221 extending downward from the lower side of the front part of the vacuum cleaner body 210, and the base end tube portion 221 is formed integrally with the vacuum cleaner body 210. Another tube is a distal tube portion 222 rotatably connected to the suction nozzle 100 in the front-to-back direction, and the remaining tube is an intermediate tube portion 223 connecting the distal tube portion 222 and the base end tube portion 221.

[0035] A dust collecting section 240 for storing dust sucked up based on the suction force of the suction source 211 is provided at the rear side relative to the base end tube 221 and at the lower side relative to the rear side portion of the vacuum cleaner body 210 containing the suction source 211. A flow outlet (not shown) opening to the rear is provided at the base end tube 221 so that dust and air flow out to the dust collecting section 240 located at the rear side relative to the base end tube 221. The dust collecting section 240 is connected to the flow outlet of the base end tube 221 in such a manner that the air flowing into the dust collecting section 240 from the flow outlet of the base end tube 221 becomes a swirling flow inside the dust collecting section 240. In detail, the dust collecting section 240 is a cylindrical container, which is connected to the flow outlet of the base end tube 221 in such a manner that the air flowing in from the flow outlet of the base end tube 221 flows along the inner circumferential surface of the dust collecting section 240. By generating a swirl flow in the dust collecting section 240 , dust contained in the air flowing into the dust collecting section 240 can be centrifugally separated.

[0036] A filter (not shown) is provided on the upper part of the dust collecting part 240. The filter is configured to allow air to flow from the dust collecting part 240 toward the suction source 211 in the cleaner body 210, and to capture dust contained in the air. As a result, the dust is retained in the dust collecting part 240.

[0037] (Structure of the nozzle)

[0038] like Figure 2 and Figure 3 As shown, the nozzle 100 has a nozzle housing 110. The nozzle housing 110 has a central portion 116 to which the distal tube portion 222 is connected, a left portion 117 extending to the left from the central portion 116, and a right portion 118 extending to the right from the central portion 116.

[0039] In detail, the nozzle housing 110 has a rear housing portion 111 extending in the left-right direction to constitute the rear portion of the central portion 116, the left portion 117, and the right portion 118, and the left housing portion 112 and the right housing portion 113 protrude forward from the left and right ends of the rear housing portion 111. The left housing portion 112 constitutes the front side portion of the left portion 117 of the nozzle housing 110, and the right housing portion 113 constitutes the front side portion of the right portion 118 of the nozzle housing 110.

[0040] The cover plate 114 is fixed to the left housing portion 112 and the right housing portion 113 at the front side relative to the rear housing portion 111. The cover plate 114 is a thin plate member that is long in the left-right direction and extends from the left portion 117 to the right portion 118 of the nozzle housing 110. When the cover plate 114 is installed, the suction space 115 divided by the rear housing portion 111, the left housing portion 112, the right housing portion 113 and the cover plate 114 is formed at the front side relative to the rear housing portion 111. That is, the suction space 115 is formed in the range from the left portion 117 to the right portion 118 of the nozzle housing 110.

[0041] The suction space 115 is provided for sucking dust on the ground and is open downward. In order to make the suction force of the suction source 211 act on the suction space 115, a Figure 4 The connecting passage 119 shown. The connecting passage 119 is provided in the portion of the central portion 116 constituting the nozzle housing 110 in the rear housing portion 111, and is extended in the front-to-rear direction. In other words, the connecting passage 119 is formed on the center line of the nozzle 100 (a line extending in the front-to-rear direction at the center of the width direction of the nozzle 100). The distal end portion 224 of the suction tube 220 (distal end tube portion 222) is connected to the rear housing portion 111 at the rear side relative to the connecting passage 119. That is, the rear housing portion 111 has a connecting portion 141 connected to the distal end portion 224 of the suction tube 220 at the rear side relative to the connecting passage 119, and the connecting portion 141 is also provided on the center line of the nozzle 100 in the same manner as the connecting passage 119.

[0042] The distal end portion 224 of the suction pipe 220 has a cross-section in the shape of an arc having a central axis extending in the left-right direction. The connection portion 141 of the rear housing portion 111 is configured to allow the distal end portion 224 to rotate around the central axis of the distal end portion 224 within a specified rotation range while holding the distal end portion 224 of the suction pipe 220. Therefore, the suction pipe 220 can be tilted in the front-rear direction within a specified range.

[0043] An opening is formed at the front side of the peripheral wall of the distal end portion 224 so as to connect the connecting passage 119 with the flow passage of the suction pipe 220. The size of the opening is set so that even if the suction pipe 220 is placed at any tilt angle, the flow passage of the suction pipe 220 is in a state of connecting with the connecting passage 119. The flow passage of the suction pipe 220 is connected with the suction space 115 via the connecting passage 119, and the suction force of the suction source 211 acts on the suction space 115.

[0044] The suction space 115 is not only used to ensure a wide area for sucking dust on the floor, but also used to arrange the brush roller 120 for sweeping the dust on the floor. Figure 3 As shown, the brush roller 120 has: a roller body 121 that is elongated in the left-right direction; and a plurality of brush rows 122 that protrude from the outer peripheral surface of the roller body 121. A rotating shaft body (not shown) protrudes from the left and right ends of the roller body 121, and the rotating shaft body is supported by the left shell portion 112 and the right shell portion 113 in a rotatable manner. In other words, the roller body 121 is rotatably supported on both sides based on the left shell portion 112 and the right shell portion 113. Each brush row 122 is formed by a plurality of bristles arranged in a spiral shape on the outer peripheral surface of the roller body 121. As shown Figure 4 As shown, most of the brush roller 120 is accommodated in the suction space 115, but the brush row 122 located at the lower side relative to the roller body 121 protrudes downward from the suction space 115 and contacts the ground. Based on the brush row, the front side portion of the nozzle housing 110 is supported in a suspended state relative to the ground. The brush row 122 is configured to have sufficient rigidity to maintain this state.

[0045] like Figure 3 As shown, in order to generate a driving force for driving the brush roller 120 to rotate, the driving unit 130 (e.g., a driving motor) is arranged in the left part of the rear housing portion 111. In addition, a transmission mechanism (e.g., a pulley and a driving belt (not shown)) for connecting the driving unit 130 and the brush roller 120 so as to transmit the driving force of the driving unit 130 to the brush roller 120 is formed in the left housing portion 112 and the rear housing portion 111. The driving unit 130 is electrically connected to the operating unit 231, and works or stops according to the operation of the operating unit 231. If the driving unit 130 works, the brush roller 120 rotates, and the rotational force of the brush roller 120 becomes a propulsion force for moving the suction nozzle 100 forward. In addition, dust is swept on the ground based on the rotation of the brush roller 120.

[0046] On the one hand, the front side portion of the nozzle housing 110 is supported based on the brush roller 120, and on the other hand, the rear side portion of the nozzle housing 110 is supported based on the brush roller 120. Figure 3The pair of left and right rear rollers 129 shown are supported in a suspended state relative to the ground. In order to arrange these rear rollers 129 at the rear side relative to the connecting portion 141, the nozzle housing 110 has a roller support portion 125 that is roughly C-shaped when viewed from above at the rear side relative to the rear housing portion 111. The pair of rear rollers 129 are rotatably mounted on the roller support portion 125. In the following description, the roller located on the left side of these rear rollers 129 is referred to as the "first rear roller 123". In addition, in the following description, the roller located on the right side is referred to as the "second rear roller 124".

[0047] The roller support portion 125 is connected to the central portion of the rear housing portion 111 in the left-right direction, and constitutes the rear portion of the central portion 116 of the nozzle housing 110. The roller support portion 125 is located at the lower side relative to the distal tube portion 222 so that the pair of rear rollers 129 are in contact with the ground, and the lower side of the roller support portion 125 is flat.

[0048] In the corners of the roller support portion 125, there are formed accommodation recesses 126 and 127 that are open downwards in order to accommodate the first rear roller 123 and the second rear roller 124. Most of the first rear roller 123 and the second rear roller 124 are accommodated in the accommodation recesses 126 and 127, but a part of the first rear roller 123 and the second rear roller 124 protrudes from the accommodation recesses 126 and 127 and contacts the ground. In this state, the first rear roller 123 and the second rear roller 124 support the nozzle housing 110 in a state where the rear side portion of the nozzle housing 110 is suspended relative to the ground.

[0049] The protrusion amount of the first rear roller 123 and the second rear roller 124 from the receiving recesses 126 and 127 is smaller than the protrusion amount of the brush roller 120 from the suction space 115. Figure 4 That is, the height of the gap between the front end of the nozzle housing 110 and the ground is greater than the height of the gap between the rear end of the roller support portion 125 and the ground.

[0050] like Figure 3As shown, the first rear roller 123 and the second rear roller 124 are mounted on the roller support portion 125 in a manner of rotating around a rotation axis inclined relative to the front-rear direction. The first rear roller 123 is configured to roll on the ground in a manner of assisting the suction nozzle 100 to move diagonally to the left front. In other words, the inclination of the rotation axis of the first rear roller 123 is set so that when the suction nozzle 100 moves forward, the first rear roller 123 receives a friction force F1 from the ground to the right rear and rolls on the ground. In addition, the second rear roller 124 is configured to roll on the ground in a manner of assisting the suction nozzle 100 to move diagonally to the right front. In other words, the inclination of the rotation axis of the second rear roller 124 is set so that when the suction nozzle 100 moves forward, the second rear roller 124 receives a friction force F2 from the ground to the left rear and rolls on the ground. For example, Figure 3 As shown, the inclination angle of the rotation axes of the first rear roller 123 and the second rear roller 124 may be set to be approximately 45° with respect to the center line of the suction nozzle 100 .

[0051] The first rear roller 123 and the second rear roller 124 are approximately symmetrical with respect to the center line of the suction nozzle 100. As described above, the connection portion 141 of the rear housing portion 111 to which the distal end portion 224 of the suction tube 220 is connected is located on the center line of the suction nozzle 100. Therefore, the distance between the connection portion 141 of the rear housing portion 111 and the first rear roller 123 is approximately equal to the distance between the connection portion 141 and the second rear roller 124.

[0052] The structure for holding the second rear roller 124 has: the structure for holding the first rear roller 123, therefore, the following reference Figure 5 Only the holding structure for the first rear roller 123 will be described.

[0053] In order to rotatably hold the first rear roller 123, a roller shaft 142 is mounted in the width direction of the housing recess 126, and a pair of hubs 146 and 147 are rotatably mounted on the roller shaft 142. These hubs 146 and 147 are arranged at intervals in the axial direction of the roller shaft 142, and the first rear roller 123 is arranged between these hubs 146 and 147. In other words, the first rear roller 123 is clamped by these hubs 146 and 147 in the axial direction of the roller shaft 142. In addition, the interval between the hubs 146 and 147 in the axial direction of the roller shaft 142 is smaller than the width of the housing recess 126. Therefore, a space is formed between the hubs 146 and 147 and the housing recess 126.

[0054] It is expected that the ring bodies 146, 147 and the first rear roller 123 are displaced in the axial direction of the roller shaft 142, and therefore, a stopper 140 is provided in the receiving recess 126 to limit the displacement to a predetermined amount or more. The stopper 140 includes a pair of stopper pieces 148, 149 arranged to face each other in the axial direction of the roller shaft 142, and a connecting piece 150 connecting the stopper pieces 148, 149 at a position spaced apart upward from the first rear roller 123. These stopper pieces 148, 149 are provided on the upper side of the roller shaft 142 and not on the lower side of the roller shaft 142 so as not to narrow the opening area of ​​the lower end of the space between the ring bodies 146, 147 and the receiving recess 126.

[0055] The stopper piece 148 is disposed facing the ring body 146 at a distance in the axial direction of the roller shaft 142. In addition, the stopper piece 149 is disposed facing the ring body 147 at a distance in the axial direction of the roller shaft 142. The interval between the stopper pieces 148 and 149 is set so that the displacement amount of the ring bodies 146, 147 and the first rear roller 123 in the axial direction of the roller shaft 142 is within the allowable range.

[0056] The stopper pieces 148 and 149 are spaced apart upward from the roller shaft 142. In addition, spaces are also formed between the stopper pieces 148 and 149 and both end surfaces of the first rear roller 123.

[0057] like Figure 3 As shown, in addition to a pair of rear rollers 129, there are also provided a left auxiliary roller 151 and a right auxiliary roller 152 for suppressing the serpentine walking when the suction nozzle 100 moves forward. The left auxiliary roller 151 is rotatably mounted on the left portion 117 of the suction nozzle 100, and the right auxiliary roller 152 is rotatably mounted on the right portion 118 of the suction nozzle 100. In detail, the left auxiliary roller 151 and the right auxiliary roller 152 are configured so that most of them are accommodated in the recesses formed in the left and right ends of the lower side surface of the rear housing portion 111 and a part of them is in a state of protruding from the recess. In addition, the rotation axes of the left auxiliary roller 151 and the right auxiliary roller 152 extend in a direction at right angles to the central axis of the suction nozzle 100, in other words, in the left and right directions.

[0058] The protrusion of the left auxiliary roller 151 and the right auxiliary roller 152 from the lower side of the nozzle housing 110 (the lower side of the rear housing portion 111) is smaller than the protrusion of the pair of rear rollers 129 from the lower side of the nozzle housing 110 (the lower side of the roller support portion 125). Therefore, when the nozzle housing 110 is not tilted to the left or right, the left auxiliary roller 151 and the right auxiliary roller 152 will be as shown. Figure 4On the other hand, if the nozzle housing 110 tilts to the left by a specified angle, the left auxiliary roller 151 will be in contact with the ground. On the contrary, if the nozzle housing 110 tilts to the right by a specified angle, the right auxiliary roller 152 will be in contact with the ground.

[0059] In addition to the inclination direction of the rotation axes of the left auxiliary roller 151 and the right auxiliary roller 152 and their protrusion amounts, the holding structure for holding the left auxiliary roller 151 and the right auxiliary roller 152 may also be different from the structure of the left auxiliary roller 151 and the right auxiliary roller 152. Figure 5 The holding structure for the first rear roller 123 shown is the same.

[0060] (Vacuum cleaner action)

[0061] When the user operates the operating part 231 , the suction source 211 of the cleaner body 210 and the driving part 130 of the nozzle 100 start to operate.

[0062] When the suction source 211 is working, the suction force of the suction source 211 acts on the suction space 115 of the suction nozzle 100 through the suction pipe 220 and the connecting passage 119 of the suction nozzle 100. As a result, the dust on the ground is sucked into the suction space 115 and flows in the connecting passage 119 and the suction pipe 220, and flows into the dust collecting section 240 together with the air. In the dust collecting section 240, the air flows in a swirling flow, and the dust contained in the air is centrifugally separated and stored in the dust collecting section 240.

[0063] When the driving unit 130 is operated, the driving force of the driving unit 130 is transmitted to the brush roller 120. As a result, the brush roller 120 rotates on the ground and can sweep the dust on the ground. In addition, since the rotation force of the brush roller 120 becomes the propulsion force for moving the suction nozzle 100 forward, the user can move the suction nozzle 100 forward with a relatively light force.

[0064] When the suction nozzle 100 moves forward, the lower side of the suction nozzle housing 110 presents a backward tilting posture, thereby forming a relatively wide space between the front end portion of the suction nozzle housing 110 and the ground. Therefore, for example, when the suction nozzle 100 moves forward on the ground covered with a carpet, the fluff of the carpet is difficult to be caught by the front end portion of the suction nozzle 100, thereby suppressing the posture of the suction nozzle 100 from changing due to the fluff of the carpet. In addition, the suction nozzle 100 can use the lower side of the suction nozzle housing 110 that presents a backward tilting posture to gradually push down the fluff of the carpet forward while moving forward. Therefore, the part located at the rear side relative to the front end portion of the suction nozzle 100 is also difficult to get stuck with the fluff of the carpet. In particular, since the lower side of the roller support portion 125 on which a pair of rear rollers 129 are installed is flat, the fluff of the carpet can remain in a state of falling forward even in the vicinity of the pair of rear rollers 129. Therefore, the fluff of the carpet can be suppressed from being rolled into the pair of rear rollers 129.

[0065] When the suction nozzle 100 moves forward on the ground, it is expected that the suction nozzle 100 will receive a force that causes the front side portion or the rear side portion of the suction nozzle 100 to bounce upward, depending on the shape of the ground.

[0066] When the front part of the suction nozzle 100 is about to bounce up, the suction nozzle 100 may tend to tilt backwards with the pair of rear rollers 129 as the axis. However, there is a connection part 141 connected to the suction pipe 220 at the front side relative to these rear rollers 129, and the downward force generated by the weight of the suction pipe 220, the cleaner body 210, the grip part 230 and the dust collecting part 240 acts on the connection part 141. Based on this downward force, the action of the suction nozzle 100 tending to tilt backwards with the pair of rear rollers 129 as the axis can be suppressed.

[0067] On the contrary, when the rear part of the suction nozzle 100 is about to bounce up, the suction nozzle 100 may be about to tilt forward with the brush roller 120 as the axis. However, such a forward tilt of the suction nozzle 100 is also suppressed based on the downward force of the connecting portion 141 acting on the rear of the brush roller 120.

[0068] Based on the downward force acting on the connecting portion 141, the pair of rear rollers 129 (the first rear roller 123 and the second rear roller 124) are subject to vertical resistance from the ground. At this time, the distances from the connecting portion 141 to the first rear roller 123 and the second rear roller 124 are approximately equal to each other. Therefore, if the nozzle housing 110 does not tilt to the left or right, the magnitudes of the vertical resistances acting on the first rear roller 123 and the second rear roller 124 become approximately equal to each other. In this case, the friction forces F1 and F2 acting symmetrically between the first rear roller 123 and the second rear roller 124 and the ground are as follows: Figure 3 As shown in the figure, the magnitudes of the friction force F1 and the friction force F2 are substantially equal. Under this force state, the rightward component of the friction force F1 and the leftward component of the friction force F2 cancel each other out. Therefore, if the nozzle housing 110 does not tilt in the left-right direction, even if the first rear roller 123 and the second rear roller 124 rotate around the inclined rotation axis, the nozzle 100 will not turn left or right and can move forward or backward straightly.

[0069] If the nozzle housing 110 does not tilt in the left-right direction, the left auxiliary roller 151 and the right auxiliary roller 152 installed in the left part 117 and the right part 118 of the nozzle housing 110 are suspended relative to the ground. Therefore, a space that allows the nozzle housing 110 to tilt to the left is formed between the left auxiliary roller 151 and the ground, and a space that allows the nozzle housing 110 to tilt to the right is formed between the right auxiliary roller 152 and the ground. Therefore, if the user operates the grip 230 in a manner that causes the suction tube 220 to tilt to the left or right, the nozzle 100 tilts to the left or right.

[0070] If the suction nozzle 100 tilts to the left, the first rear roller 123 is pressed against the ground with a stronger force than the second rear roller 124. As a result, the friction force F1 of the first rear roller 123 is greater than the friction force F2 of the second rear roller 124. In this state, if the tilt of the suction nozzle 100 to the left is maintained at a level where the left auxiliary roller 151 does not contact the ground, the direction of travel of the suction nozzle 100 is strongly affected by the rotation direction of the first rear roller 123. Therefore, the suction nozzle 100 moves in the opposite direction to the direction of the friction force F1, that is, diagonally to the left and forward.

[0071] If the suction nozzle 100 further tilts to the left, the left auxiliary roller 151 comes into contact with the ground. Unlike the first rear roller 123 that rotates around an axis that is tilted relative to the center line of the suction nozzle 100, the left auxiliary roller 151 rotates around an axis that is perpendicular to the center line of the suction nozzle 100. Therefore, when the suction nozzle 100 moves diagonally forward to the left, the left auxiliary roller 151 does not rotate like the first rear roller 123. That is, the left auxiliary roller 151, in a state of contact with the ground, hinders the movement of the suction nozzle 100 diagonally forward to the left.

[0072] When the suction nozzle 100 is tilted to the right, the action of the suction nozzle 100 is bilaterally symmetrical to the case where the suction nozzle 100 is tilted to the left.

[0073] It is expected that the suction nozzle 100 may accidentally tilt to the left and / or right based on the shape of the ground. In this case, the suction nozzle 100 may accidentally turn left or right while moving forward or moving in a serpentine manner to the left or right. However, if the left auxiliary roller 151 and the right auxiliary roller 152 are in contact with the ground, these unexpected movements are suppressed.

[0074] The first rear roller 123 and the second rear roller 124 roll on the ground, so it is expected that dust attached to these rear rollers from the ground will enter the receiving recesses 126 and 127 and accumulate in the receiving recesses 126. In order to easily remove the dust accumulated in the receiving recesses 126 and 127, the stoppers 148 and 149 are provided at the upper side relative to the roller shaft 142 in the receiving recesses 126 and 127. That is, by configuring the stoppers 148 and 149 in this way, the opening area of ​​the lower end of the receiving recesses 126 and 127 is not narrowed by the stoppers 148 and 149. Therefore, it is easy to insert a tool for removing dust (such as tweezers) into the receiving recesses 126 and 127.

[0075] A space is formed between the stoppers 148, 149 and the roller 142. However, if the dust is smaller than the space, it is difficult for the dust to be captured by the space. Even if the dust enters the space and is clamped between the stoppers 148, 149 and the roller 142, it is difficult for the dust to be compressed by them with a strong force. Therefore, the user can remove the dust between the stoppers 148, 149 and the roller 142 with a small force.

[0076] When the first rear roller 123 or the second rear roller 124 moves toward the stopper 148, the stopper 148 comes into contact with the ring body 146 facing the stopper 148. At this time, the stopper 148 is separated from the end face of the first rear roller 123 or the second rear roller 124 facing the stopper 148 by a gap corresponding to the thickness of the ring body 146. When the first rear roller 123 or the second rear roller 124 moves in the reverse direction, the stopper 149 is separated from the end face of the first rear roller 123 or the second rear roller 124 facing the stopper 149. If the dust is smaller than the space between the stopper 148, 149 and the end face of the first rear roller 123 or the second rear roller 124, the dust is not sandwiched by the stopper 148, 149 and the first rear roller 123 or the second rear roller 124 and is captured. Therefore, the dust is accumulated in the receiving recess. In addition, even if the dust becomes the state of being compressed by the clamping of the stopper 148,149 and the 1st rear roller 123 or the 2nd rear roller 124, the compression force received by the dust can not be too strong, so the user can remove the dust with less power.

[0077] In the above-mentioned embodiment, a pair of rear rollers 129 are provided. As an alternative, Figure 6 As shown, the suction nozzle 100 may have a single rear roller 129. Thus, the suction nozzle 100 can be simplified.

[0078] In this case, the protrusion amount of the rear roller 129 from the lower side of the roller support portion 125 is set smaller than the protrusion amount of the brush roller 120 from the suction space 115, similarly to the first rear roller 123 and the second rear roller 124. As a result, the lower side of the nozzle housing 110 is tilted backward.

[0079] When a single rear roller 129 is used, the rear roller 129 is arranged on the center line of the suction nozzle 100. As a result, the suction nozzle 100 is prevented from easily tilting to the left or the right. In addition, the rear roller 129 can be configured to rotate around a rotation axis that is at right angles to the center line of the suction nozzle 100. In this case, the suction nozzle 100 is prevented from easily turning to the left or the right when moving forward. Figures 1 to 5 In the suction nozzle 100 shown, the left auxiliary roller 151 and the right auxiliary roller 152 provided to suppress meandering may be omitted.

[0080] like Figure 7 As shown in FIG. 1 , the suction nozzle 100 may have inclined rollers 154 and 155 in addition to the first rear roller 123 and the second rear roller 124, which are located at the front side relative to the first rear roller 123 and the second rear roller 124. The inclined roller 154 is arranged to be point-symmetrical with the second rear roller 124 with respect to the intersection point P of the rotation axes of the first rear roller 123 and the second rear roller 124. The inclined roller 155 is arranged to be point-symmetrical with the first rear roller 123 with respect to the intersection point P.

[0081] The protrusion amounts of the first rear roller 123, the second rear roller 124, and the inclined rollers 154 and 155 from the lower side of the nozzle housing 110 are set so that when they are in contact with the ground with a uniform force, the lower side of the nozzle housing 110 is in a backward tilted posture. Therefore, the protrusion amounts of the inclined rollers 154 and 155 located on the front side relative to the first rear roller 123 and the second rear roller 124 are greater than the protrusion amounts of the first rear roller 123 and the second rear roller 124.

[0082] When the inclined rollers 154 and 155 are provided, the connection portion 141 to which the suction pipe 220 is connected is provided at the intersection P. In this state, if the user operates the grip portion 230 as shown in FIG. Figure 7 When the connecting portion 141 is rotated clockwise as shown by the arrow in FIG. 1 , the suction nozzle 100 also rotates around the intersection point P, and the orientation of the suction nozzle 100 changes. At this time, the first rear roller 123, the second rear roller 124, and the inclined rollers 154 and 155 rotate in a manner that does not hinder the change of the orientation of the suction nozzle 100. Therefore, the operation for changing the orientation of the suction nozzle 100 can be easily performed.

[0083] Furthermore, when the user moves the suction nozzle 100 forward, the component of the friction force received by the first rear roller 123 from the ground is directed to the right, while the component of the friction force of the inclined roller 154 located in front of the first rear roller 123 is directed to the left. Therefore, the components of the force of the first rear roller 123 and the inclined roller 154 cancel each other out. Similarly, the components of the friction force of the second rear roller 124 and the inclined roller 155 in the left and right directions also cancel each other out. Therefore, it is difficult for the suction nozzle 100 to turn left or right when moving forward, and the serpentine movement of the suction nozzle 100 is suppressed. Therefore, when the inclined rollers 154 and 155 are provided, Figures 1 to 5 In the suction nozzle 100 shown, the left auxiliary roller 151 and the right auxiliary roller 152 provided to suppress meandering may be omitted.

[0084] <Second Embodiment>

[0085] When the brush roller 120 rotates while the suction nozzle 100 is suspended relative to the ground, it is expected that the brush roller 120 may come into contact with a portion other than the ground. For example, if the brush roller 120 comes into contact with a curtain, the curtain may be rolled into the brush roller 120. In order to prevent such an undesirable state, it is preferred to control the brush roller 120 so that it does not rotate while the suction nozzle 100 is suspended relative to the ground. Therefore, Figure 8 The suction nozzle 100 shown is configured to detect whether the suction nozzle 100 is suspended relative to the ground, and to prevent the brush roller 120 from rotating when the suction nozzle 100 is suspended relative to the ground.

[0086] (Configuration of a portion for detecting the state of a nozzle)

[0087] The suction nozzle 100 includes the movable portion 160 , the position detection portion 161 , the drive control portion 162 , and the movable roller 164 , and thereby prevents the brush roller 120 from rotating when the suction nozzle 100 is suspended from the floor.

[0088] In order to arrange the movable part 160, an opening recess 163 opening downward is provided on the lower side of the rear housing part 111. The movable part 160 is installed in the nozzle housing 110 in the opening recess 163 and can swing up and down. The movable part 160 rotates downward due to its own weight when the nozzle 100 is separated from the ground. Figure 8 As shown in FIG. 1 , the recessed portion 163 is protruded from the opening. Figure 8 The position of the movable part 160 shown in FIG. 1 is referred to as a "protruding position". On the other hand, in the grounded state where the suction nozzle 100 is in contact with the ground, the movable part 160 is pushed up based on the ground, such as Fig. 9 As shown in FIG. 1 , the PCB is in a state of being immersed in the opening recess 163. In the following description, Fig. 9 The position of the movable part 160 shown is referred to as the "recessed position".

[0089] The movable portion 160 accommodates a portion of the movable roller 164 and holds the movable roller 164 in a manner that allows the movable roller 164 to rotate about a rotation axis extending in the left-right direction. Fig.10 As shown, the movable roller 164 is configured to be narrower in width than the pair of rear rollers 129 , and the ground contact area of ​​the movable roller 164 is smaller than the ground contact area of ​​the rear rollers 129 .

[0090] The movable part 160 has: a left support plate 166 arranged on the left side relative to the movable roller 164; and a right support plate 167 arranged on the right side relative to the movable roller 164. The left support plate 166 and the right support plate 167 are arranged at intervals on the left and right, so that most of the movable roller 164 is accommodated in the internal space between them. The left support plate 166 and the right support plate 167 have: when the movable part 160 is placed in the submerged position (that is, when the suction nozzle 100 is in the grounded state), a lower end surface 168 facing the ground. When the movable part 160 is placed in the submerged position, a part of the movable roller 164 protrudes from the lower end surface 168, and the movable roller 164 can roll on the ground when the suction nozzle 100 moves forward on the ground. Therefore, the movable part 160 itself does not contact the ground.

[0091] The movable portion 160 is configured to control the displacement of the movable roller 164 in the direction along the rotation axis of the movable roller 164 (left-right direction) within a specified value. Fig.11 As shown, the left stopper 171 and the right stopper 172 are also provided. The left stopper 171 protrudes to the right from the right side of the left support plate 166, and the right stopper 172 protrudes to the left from the left side of the right support plate 167. The left stopper 171 and the right stopper 172 form a part of the lower end surface 168, and the space between them forms a first opening 173 for the movable roller 164 to protrude.

[0092] If the movable part 160 is rotated to the protruding position, Fig.12 As shown, a front end surface 175 (the surface on the brush roller 120 side) that is substantially at a right angle to the lower end surface 168 protrudes from the opening recess 163. When the movable portion 160 is placed in the retracted position, the front end surface 175 is in a state of entering the opening recess 163. A second opening 174 having a larger width than the first opening 173 is formed on the front end surface 175. The second opening 174 is provided to facilitate removal of dust that has entered the movable portion 160.

[0093] The position detection unit 161 and the drive control unit 162 are arranged in the rear housing portion 111. The position detection unit 161 is configured to detect whether the movable portion 160 is in the submerged position or in the protruding position, and output a signal indicating the position of the movable portion 160 to the drive control unit 162. The position detection unit 161 can be configured, for example, by a mechanical switch or an optical sensor. The drive control unit 162 is configured to request the drive unit 130 to operate based on the user operating the operation unit 231, and to operate the drive unit 130 on the condition that the position detection unit 161 detects that the movable portion 160 is in the submerged position. Therefore, when the user does not request the drive unit 130 to operate, or when the position detection unit 161 detects that the movable portion 160 is in the protruding position, the drive control unit 162 does not operate the drive unit 130.

[0094] The drive control unit 162 may be composed of a control substrate equipped with a CPU (Central Processing Unit), or may be composed of a hard logic circuit. The hard logic circuit may include one or more semiconductor chips. A microcomputer and peripheral circuits may also be used in combination with the hard logic circuit.

[0095] (Movement of sucking the nozzle)

[0096] When the nozzle 100 is in contact with the ground, if the user operates the operating unit 231 and requests the driving unit 130 to work, the driving unit 130 works and the brush roller 120 rotates. At this time, the brush roller 120 sweeps the dust on the ground and generates a propulsion force to move the nozzle 100 forward by contacting the ground.

[0097] While the suction nozzle 100 is moving forward, the movable roller 164 rolls on the ground. Therefore, it is difficult for the movable part 160 to damage the ground. Since the rotating shaft of the movable roller 164 extends in the left-right direction, the movable roller 164 may hinder the action of the suction nozzle 100 turning left or right while moving forward. However, since the width of the movable roller 164 is narrower than the pair of rear rollers 129, the friction between the movable roller 164 and the ground is relatively small. Therefore, the resistance of the movable roller 164 to the action of the suction nozzle 100 turning left or right while moving forward will not become too large.

[0098] The resistance of the movable roller 164 to the action of the suction nozzle 100 turning left or right while moving forward is small, but it has a certain degree of size. Based on this resistance, the movable roller 164 may move due to the force along the direction of the rotating shaft of the movable roller 164. If the movable roller 164 moves, the left stopper 171 or the right stopper 172 contacts the side end surface of the movable roller 164 to limit the movement of the movable roller 164. In this way, since the left stopper 171 and the right stopper 172 are provided to limit the movement of the movable roller 164, the width of the first opening 173 between the left stopper 171 and the right stopper 172 is relatively narrow. Therefore, during the rolling of the movable roller 164, even if the lower end surface 168 formed with the first opening 173 faces the ground, dust on the ground is difficult to enter the movable part 160.

[0099] When the user operates the operation unit 231 to request the driving unit 130 to stop or to lift the suction nozzle 100 upward, the driving control unit 162 stops the driving unit 130. As a result, the brush roller 120 also stops.

[0100] When the brush roller 120 is stopped, the user can remove dust from the movable part 160 without being drawn into the brush roller 120. In this dust removal operation, the user can pull the movable part 160 out of the opening recess 163 with a finger, so that the front end face 175 of the movable part 160 protrudes from the opening recess 163. Since a relatively wide second opening 174 is formed on the front end face 175, the user can easily access the inner space of the movable part 160 through the second opening 174, and can remove dust in the inner space of the movable part 160. In addition, the second opening 174 is relatively wide, but during the period when the suction nozzle 100 moves on the ground, the front end face 175 formed with the second opening 174 is in a state of entering the opening recess 163. Therefore, it is difficult for dust to invade through the second opening 174.

[0101] <Third Embodiment>

[0102] In order to generate a propulsion force for advancing the suction nozzle 100 by the rotation of the brush roller 120, the brush roller 120 moves along the Figure 4 When the brush roller 120 rotates on a carpeted floor, it is expected that the fluff of the carpet will be caught between the brush roller 120 and the rear housing portion 111. In order to prevent the fluff of the carpet from being caught between the brush roller 120 and the rear housing portion 111, the suction nozzle 100 can be as follows: Fig.13 Improve as shown.

[0103] Fig.13 The rear housing portion 111 of the suction nozzle 100 shown has a partition wall 176 that divides the rear end of the suction space 115. The upper portion of the partition wall 176 is in an upright position, and the lower portion of the partition wall 176 is in a forward-leaning position away from the brush roller 120 as it goes downward. Therefore, the pile of the carpet is difficult to be clamped between the brush roller 120 and the rear housing portion 111.

[0104] like Fig.14 As shown, a sliding belt 178 that rubs the ground as the suction nozzle 100 moves may also be provided at the lower part of the partition wall 176. The sliding belt 178 protrudes downward from the groove portion recessed in the lower part of the partition wall 176. The protrusion of the sliding belt 178 is set to be greater than the protrusion of the pair of rear rollers 129, and the suction nozzle housing 110 is also maintained based on the sliding belt 178 when it is in a backward tilted posture. In addition, the sliding belt 178 can be longer in the left and right direction. The sliding belt 178 can be formed of a plurality of soft materials such as bristles or felt cloth.

[0105] Slide band 178 rubs with the ground when suction nozzle 100 moves, therefore, improved the cleaning ability to the ground. In addition, because slide band 178 is formed by soft material, therefore, even if slide band 178 rubs with the ground, the ground is also difficult to be damaged.

[0106] Fig.13 and Fig.14 The structures of the partition wall 176 and the sliding belt 178 shown are applicable to the suction nozzle 100 of the first embodiment and the second embodiment.

[0107] <Fourth embodiment>

[0108] In the first to third embodiments, the nozzle 100 has a single brush roller 120. As an alternative, Fig.15 As shown, the nozzle 100 may include a pair of left and right first brush roller 181 and second brush roller 182 .

[0109] The first brush roller 181 and the second brush roller 182 have an axial length shorter than half the length of the suction space 115 in the left-right direction, and are arranged symmetrically in the suction space 115 with a gap between the left and right sides. In addition, drive motors 183 and 184 for the first brush roller 181 and the second brush roller 182 are arranged in the rear housing portion 111, and these drive motors 183 and 184 constitute the drive unit 130. Moreover, a transmission mechanism (not shown) for transmitting the driving force of the drive motor 183 to the first brush roller 181 is formed in the left housing portion 112 and the rear housing portion 111. In addition, a transmission mechanism (not shown) for transmitting the driving force of the drive motor 184 to the second brush roller 182 is formed in the right housing portion 113 and the rear housing portion 111.

[0110] The second brush roller 182 has a structure that is bilaterally symmetrical with the first brush roller 181 , and therefore only the structure of the first brush roller 181 will be described below.

[0111] The first brush roller 181 located on the left side is supported on one side by the left housing portion 112 in a rotatable manner. The first brush roller 181 is connected to the left housing portion 112 in a manner to rotate around a rotation axis that tilts forward as it moves from the left housing portion 112 to the right. When the first brush roller 181 rotates around such an inclined rotation axis, Fig.15 As shown, the force F3 directed to the right oblique rear is transmitted to the ground. In addition, the reaction force of the force F3 becomes a propulsion force acting on the suction nozzle 100 through the first brush roller 181. At this time, the friction force F1 between the first rear roller 123 and the ground is also directed to the right oblique rear.

[0112] The second brush roller 182 is symmetrical with the first brush roller 181, so the force F4 applied to the ground when the first brush roller 181 rotates is directed to the left and rear. In addition, the reaction force of the force F4 becomes a propulsion force acting on the suction nozzle 100 through the second brush roller 182. At this time, the friction force F2 between the second rear roller 124 and the ground is also directed to the left and rear.

[0113] When the nozzle housing 110 is not tilted left or right, the first brush roller 181 and the second brush roller 182 are pressed against the ground with a substantially uniform force. As a result, the forces F3 and F4 of the first brush roller 181 and the second brush roller 182 are substantially equal in magnitude. Therefore, the rightward component of the force F3 and the leftward component of the force F4 cancel each other out, and the nozzle 100 is difficult to turn left or right when moving forward.

[0114] If the nozzle housing 110 tilts to the left, the first brush roller 181 located on the left side is pressed to the ground with a stronger force than the second brush roller 182 located on the right side. As a result, the force F3 of the first brush roller 181 is greater than the force F4 of the second brush roller 182. At this time, the friction force F1 of the first rear roller 123 is also greater than the friction force F2 of the second rear roller 124. Therefore, the direction of travel of the nozzle 100 is strongly affected by the first brush roller 181 and the first rear roller 123 rather than the second brush roller 182 and the second rear roller 124. Since the force F3 of the first brush roller 181 and the friction force F1 of the first rear roller 123 are both directed to the right oblique rear, these force components are all directed to the right. Therefore, by tilting the nozzle housing 110 to the left, the nozzle 100 can easily turn left while moving forward. On the contrary, if the nozzle housing 110 is tilted to the right, the nozzle housing 110 can easily turn to the right while moving forward.

[0115] Fig.15 The first brush roller 181 and the second brush roller 182 shown are configured to rotate around a rotation axis that is tilted forward relative to the left-right direction. As an alternative, the first brush roller 181 and the second brush roller 182 may also be configured to rotate around a rotation axis that is not tilted relative to the left-right direction. In this case, the spiral shape of the brush row 122 of the first brush roller 181 can be set so that a force F3 directed obliquely to the right rear can be obtained when the brush row 122 contacts the ground. In addition, the spiral shape of the brush row 122 of the second brush roller 182 can be set so that a force F4 directed obliquely to the left rear can be obtained when the brush row 122 contacts the ground. As a further alternative, both the inclination of the rotation axis of the first brush roller 181 and the second brush roller 182 and the spiral shape of the brush row 122 of these brush rollers can be set in a manner that can obtain left-right symmetrical forces F3 and F4.

[0116] The configurations related to the first brush roller 181 and the second brush roller 182 can be applied to the suction nozzles 100 of the first to third embodiments.

[0117] In the first to fourth embodiments, the vacuum cleaner 200 is a stick type. Alternatively, the vacuum cleaner 200 may be a canister type.

[0118] (Effects, etc.)

[0119] The suction nozzle 100 according to the above-described embodiment has the following features and has the following effects.

[0120] One aspect of the above-mentioned embodiment involves a nozzle that can be used in a suction-type vacuum cleaner. The nozzle includes: a nozzle housing, which forms a suction space that opens downward so that dust on the ground can be sucked in; a driving unit that generates a driving force; a brush roller that is rotatably supported by the nozzle housing in a state that can contact the ground, and rotates based on the driving force of the driving unit, thereby sweeping the dust on the ground while generating a propulsion force to move the nozzle forward; and a rear roller that is rotatably mounted on the nozzle housing in a manner that rolls on the ground at the rear side relative to the brush roller when the nozzle moves forward. The brush roller and the rear roller support the nozzle housing in a manner that causes the lower side of the nozzle housing to be in a backward tilted posture that is downwardly descending.

[0121] According to the above-mentioned structure, the nozzle housing is supported by the brush roller and the rear roller in a manner that the lower side of the nozzle housing is in a backward tilted posture descending toward the rear, so that a relatively large gap can be formed between the front end of the nozzle housing and the ground. Therefore, when the nozzle moves forward on a carpeted floor, for example, it is difficult for the fluff of the carpet to be caught by the front end of the nozzle housing. Therefore, it is difficult for the posture of the nozzle to be lost due to the fluff of the carpet being caught by the front end of the nozzle housing, so the nozzle can move forward on the carpeted floor with a stable posture. In this case, since the contact state between the carpet and the brush roller is stable, it is difficult for the propulsion force transmitted from the brush roller to the ground to become too weak when the driving unit rotates the brush roller. That is, the nozzle can move forward on the ground while obtaining the propulsion force with suppressed changes from the brush roller. Moreover, when the nozzle moves forward on the carpet laid on the ground, the pile of the carpet that enters the lower side of the nozzle shell gradually falls down based on the lower side of the nozzle shell in the backward tilted posture, so the advancement of the nozzle is less likely to be hindered by the pile of the carpet.

[0122] In the above configuration, the vacuum cleaner may include a suction pipe having a flow path for the dust sucked through the suction space to flow, and the nozzle housing may be configured to be connectable to the suction pipe at a position located in front of the rear roller and in the rear of the brush roller.

[0123] When the nozzle housing tilts toward the rear side with the rear roller as the axis, the brush roller located at the front side relative to the rear roller will be in a state of being spaced apart from the ground. In addition, when the nozzle housing tilts toward the front side with the brush roller as the axis, the rear roller located at the rear side relative to the brush roller will be in a state of being spaced apart from the ground. In order to avoid these undesirable states, in the above-mentioned structure, the suction tube is connected to the nozzle housing at the front side relative to the rear roller and at the rear side relative to the brush roller. At this connection portion, the user can apply a downward force to press the nozzle to the ground through the suction tube. If a downward force is applied at a position located at the front side relative to the rear roller and at the rear side relative to the brush roller, the above-mentioned tilting can be suppressed.

[0124] In the above configuration, the suction nozzle may further include: a second rear roller, which is rotatably mounted on the suction nozzle housing at the left or right side relative to the rear roller, i.e., the first rear roller. The first rear roller may be as follows: it can roll on the ground around a rotation axis that is inclined in a manner to assist the suction nozzle to move diagonally to the left or diagonally to the front. The second rear roller may be as follows: it rotates around a rotation axis that is symmetrical to the rotation axis of the first rear roller, and can roll on the ground in a manner to assist the suction nozzle to move diagonally to the right or diagonally to the front.

[0125] According to the above configuration, the rotation axes of the first rear roller and the second rear roller are symmetrical. Therefore, when the suction nozzle moves forward in a state where the first rear roller and the second rear roller are pressed against the ground with equal forces, the left and right forces transmitted from the first rear roller and the second rear roller to the ground cancel each other out. Therefore, the suction nozzle can move forward without turning left or right.

[0126] On the other hand, if the suction nozzle is tilted to the left or right, one of the first rear roller and the second rear roller will be pressed to the ground with a stronger force than the other. In this case, the direction of travel of the suction nozzle will be strongly affected by the roller pressed to the ground with a stronger force. Therefore, if the roller pressed to the ground with a stronger force rolls on the ground around a rotating shaft tilted in a manner to assist the suction nozzle to move diagonally to the left and front, the suction nozzle can move diagonally to the left and front with a lighter force. On the contrary, if the roller rolls on the ground around a rotating shaft tilted in a manner to assist the suction nozzle to move diagonally to the right and front, the suction nozzle can move diagonally to the right and front with a lighter force.

[0127] In the above-mentioned structure, the vacuum cleaner may include: a suction pipe, which forms a flow channel for the dust sucked through the suction space to flow. The nozzle may also include: a second rear roller, which is located on the left or right side relative to the rear roller, that is, the first rear roller, and can be rotatably mounted on the nozzle housing. The first rear roller may be as follows: it can roll on the ground around a rotating shaft inclined in a manner to assist the nozzle to move diagonally to the left front or diagonally to the right front. The second rear roller may be as follows: it rotates around a rotating shaft that is symmetrical with the rotating shaft of the first rear roller, and can roll on the ground in a manner to assist the nozzle to move diagonally to the right front or diagonally to the left front. The nozzle housing may have: a connecting portion, which is configured to be connected to the suction pipe at the rear side relative to the brush roller. The connecting portion may be set at a position located at the front side relative to the first rear roller and the second rear roller and at a position that is the same distance away from the first rear roller and the second rear roller.

[0128] According to the above-mentioned structure, when the user presses the suction nozzle to the ground through the suction tube and moves it forward, the user's force is transmitted to the suction nozzle through the connection part connected to the suction tube. At this time, since the distances from the connection part to the first rear roller and the second rear roller are equal to each other, the first rear roller and the second rear roller are pressed to the ground with approximately equal forces. In this case, since the magnitudes of the left and right forces generated from the first rear roller and the second rear roller are approximately equal, these left and right forces are easily offset. Therefore, when the user moves the suction nozzle forward, it is difficult for the suction nozzle to turn left or right.

[0129] In the above-mentioned structure, the nozzle housing may have: a central portion provided with a connection portion; a left portion extending from the central portion to the left; and a right portion extending from the central portion to the right. The first rear roller and the second rear roller may be mounted on the central portion in such a manner that the left portion and the right portion are off the ground, thereby allowing the nozzle housing to tilt based on the left and right tilting of the suction tube when the suction tube tilts to the left or right. The first rear roller and the second rear roller may be as follows: of the first rear roller and the second rear roller, the roller located on the left side can roll on the ground around a rotating shaft tilted in such a manner as to assist the suction nozzle to move diagonally to the left and front, and the roller located on the right side can roll on the ground around a rotating shaft tilted in such a manner as to assist the suction nozzle to move diagonally to the right and front.

[0130] According to the above configuration, since the first rear roller and the second rear roller are installed in the central part of the nozzle housing, the nozzle can be supported on the ground in a state where the left and right parts of the nozzle housing are off the ground. If a space is formed between the left and right parts of the nozzle housing and the ground, the nozzle housing is allowed to tilt left and right. Therefore, if the user tilts the suction tube left and right, the nozzle housing can tilt left and right based on the tilting.

[0131] If the nozzle housing is tilted to the left, the roller on the left of the first and second rear rollers is pressed against the ground more strongly than the roller on the right. In this state, the roller on the left has a greater influence on the direction of travel of the nozzle than the roller on the right. Therefore, by the user tilting the suction tube to the left, the nozzle can move diagonally to the left front. On the contrary, if the user tilts the suction tube to the right, the nozzle can move diagonally to the right front.

[0132] In the above-mentioned structure, the suction nozzle may further include: a second brush roller, which is disposed in a left-right symmetrical manner with the brush roller, i.e., the first brush roller, in the suction space, and is supported by the suction nozzle housing in a rotatable manner in a state of being able to contact the ground, and is driven to rotate based on the driving unit. The first brush roller and the second brush roller may be as follows: of the first brush roller and the second brush roller, the brush roller located on the left side rotates around a rotating shaft tilted in a manner to generate a propulsion force in a direction that moves the suction nozzle obliquely to the left front when driven by the driving unit, and the brush roller located on the right side rotates around a rotating shaft tilted in a manner to generate a propulsion force in a direction that moves the suction nozzle obliquely to the right front when driven by the driving unit.

[0133] In the above-mentioned structure, the suction nozzle may further include: a second brush roller, which is arranged in a left-right symmetrical manner with the brush roller, i.e., the first brush roller, in the suction space, and is supported by the suction nozzle housing so as to be rotatable in a state of being able to contact the ground, and is rotationally driven based on the driving unit. The first brush roller and the second brush roller may respectively include: a roller body, which is extended in the left-right direction; and a brush row, which protrudes from the outer peripheral surface of the roller body. The first brush roller and the second brush roller may be as follows: of the first brush roller and the second brush roller, the brush row of the brush roller located on the left side is extended in such a manner that when driven by the driving unit, the brush row contacts the ground and generates a propulsion force in a direction that moves the suction nozzle obliquely to the left front, and the brush row of the brush roller located on the right side is extended in such a manner that when driven by the driving unit, the brush row contacts the ground and generates a propulsion force in a direction that moves the suction nozzle obliquely to the right front.

[0134] According to the above configuration, the first brush roller and the second brush roller are arranged symmetrically. Therefore, if these brush rollers are driven to rotate while being in contact with the ground with a uniform force, the left and right components of the propulsion force brought by the first brush roller and the second brush roller cancel each other out. Therefore, if these brush rollers are driven to rotate by the driving unit while being in contact with the ground with a uniform force, the suction nozzle can move forward straightly.

[0135] On the other hand, if the nozzle housing is tilted to the left, the brush roller on the left side contacts the ground more strongly than the brush roller on the right side. Therefore, the propulsion force brought by the brush roller on the left side is stronger than the propulsion force brought by the brush roller on the right side, and the nozzle can move forward while turning left. At this time, the roller on the left side of the first rear roller and the second rear roller is pressed against the ground more strongly than the roller on the right side, and the influence of the roller on the left side is stronger. The roller on the left side assists the movement of the nozzle diagonally to the left and front, and assists the movement of the nozzle in the same direction as the propulsion force brought by the brush roller on the left side. Therefore, the nozzle can easily move forward while turning left. On the contrary, if the nozzle housing is tilted to the right side, the nozzle can easily turn right while moving forward.

[0136] In the above-mentioned configuration, the suction nozzle may further include: a left auxiliary roller, which is mounted on the left part in a manner that allows rotation around a rotating shaft extending in the left-right direction; and a right auxiliary roller, which is mounted on the right part in a manner that allows rotation around a rotating shaft extending in the left-right direction. The left auxiliary roller and the right auxiliary roller may be in a suspended state relative to the ground when the suction nozzle housing is not tilted in the left-right direction. The left auxiliary roller may be as follows: when the suction nozzle housing is tilted to the left by a specified angle, the left auxiliary roller contacts the ground. The right auxiliary roller may be as follows: when the suction nozzle housing is tilted to the right by a specified angle, the right auxiliary roller contacts the ground.

[0137] According to the above-mentioned structure, the left auxiliary roller contacts the ground when the nozzle housing is tilted to the left at a specified angle. In this state, since the left auxiliary roller can rotate around the rotating shaft extending in the left-right direction, it will not hinder the movement of the nozzle in the front-to-back direction, but on the other hand, hinder the movement of the nozzle in the left-to-right direction. Similarly, when the nozzle housing is tilted to the right at a specified angle, the right auxiliary roller allows the movement of the nozzle in the front-to-back direction, but hinders the movement of the nozzle in the left-to-right direction. On the other hand, when the nozzle is tilted to the extent that the left auxiliary roller and the right auxiliary roller are not in contact with the ground, the nozzle will not be hindered by the left auxiliary roller and the right auxiliary roller and can move forward while turning left or right.

[0138] In the above configuration, a receiving recess opening downward may be formed in the nozzle housing, and the receiving recess may receive the rear roller in a state where a portion of the rear roller protrudes from the lower side of the nozzle housing. The nozzle may further include: a roller shaft rotatably supporting the rear roller in the receiving recess; and a stopper limiting the displacement of the rear roller by more than a specified amount in the axial direction of the roller shaft. The stopper may be arranged on the upper side relative to the roller shaft.

[0139] According to the above-mentioned structure, since a part of the rear roller accommodated in the accommodating recess protrudes from the lower side of the nozzle housing, the rear roller can contact the ground and roll on the ground. In this case, the dust attached to the rear roller will enter the accommodating recess, and dust will accumulate in the accommodating recess. In order to allow the user to easily remove the dust in the accommodating recess, it is more ideal to increase the opening width of the accommodating recess. However, if the opening width of the accommodating recess is simply widened, the rear roller will be displaced significantly along the roller axis and the direction of travel of the nozzle will accidentally swing left and right. In order to limit the displacement of such a rear roller, a stopper is provided. The stopper is arranged on the upper side relative to the roller axis, and therefore, the opening portion of the lower end of the accommodating recess will not be narrowed. Therefore, the user can contact the inside of the accommodating recess through the opening portion of the lower end of the accommodating recess, and can remove the dust in the accommodating recess.

[0140] In the above configuration, the stopper may be provided in the housing recess in a state where the stopper is spaced apart from the roller shaft.

[0141] According to the above configuration, since the stopper is spaced apart from the roller shaft, dust smaller than the space between the stopper and the roller shaft is difficult to be captured by the space. In addition, even if dust larger than the space is compressed and sandwiched in the space, the compression force acting on the dust will not become too large, and the user can remove the dust with a relatively light force.

[0142] In the above configuration, the suction nozzle 100 may further include: a pair of ring bodies, which are arranged in a manner to clamp the rear roller in the axial direction of the roller shaft. The stopper may include: a pair of stopper plates, which are arranged in a manner to be spaced apart from the pair of ring bodies and to face the pair of ring bodies. Each stopper plate is configured to limit the displacement of the rear roller in the axial direction of the roller shaft by abutting against the ring body facing the stopper plate in a state where the stopper plate is spaced apart from the rear roller.

[0143] According to the above configuration, a pair of stoppers and a pair of ring bodies are disposed facing each other. When the ring body and the rear roller are displaced toward one of the stoppers, if the ring body abuts against the stopper, the displacement of the rear roller in the axial direction of the roller shaft can be restricted.

[0144] In order to limit the displacement of the rear roller in the axial direction of the roller shaft, a structure in which the stopper is in contact with the rear roller can also be considered, but in this case, a space cannot be formed between the stopper and the rear roller. On the other hand, in the case of adopting a structure in which the stopper is in contact with the ring body, a space can be formed between the rear roller and the stopper. If the dust attached to the rear roller is smaller than the space, it will not remain in the space in a clamped state. If the dust larger than the space is clamped in a compressed state by the rear roller and the stopper, the compressive force acting on the dust will not be too large, and the user can remove the dust with less force.

[0145] In the above-mentioned structure, an opening recess opening downward may be formed in the nozzle housing. The nozzle may also include: a movable part, which is installed on the nozzle housing in such a manner that the movable part is placed in a protruding position protruding from the opening recess when the nozzle is in a separated state with a gap relative to the ground, and is placed in a submerged position sunken into the opening recess from the protruding position when the nozzle is in a grounded state in contact with the ground; a position detection part, which detects whether the movable part is placed in the submerged position; and a drive control part, which operates the drive part on the condition that the position detection part detects that the movable part is placed in the submerged position.

[0146] According to the above-mentioned structure, when the suction nozzle is in a grounded state in contact with the ground, the movable part is pushed upward based on the ground, and the movable part is in a state of being submerged in the opening recess. On the other hand, if the suction nozzle leaves the ground, the movable part is in a protruding position protruding from the opening recess. By detecting the position of such a movable part by the position detection unit, it is possible to understand whether the suction nozzle is in a grounded state. That is, if the position detection unit detects that the movable part is in the submerged position, the suction nozzle is in a grounded state. In this state, even if the driving unit rotates the brush roller, the curtains and the like will not be rolled into the brush roller. Therefore, the drive control unit operates the drive unit on the condition that the position detection unit detects that the movable part is in the submerged position.

[0147] In the above-mentioned structure, the suction nozzle may further include: a movable roller, which is held by the movable part in a manner that the movable roller rolls on the ground when in the grounded state. The movable part may be formed with: an internal space for accommodating the movable roller; a first opening for exposing the movable part from the opening recess in a state where the movable part faces the ground when the movable part is placed in the submerged position; and a second opening for allowing the movable part to enter the opening recess when the movable part is placed in the submerged position, and exposing the movable part from the opening recess when the movable part is placed in the protruding position. The first opening may have a size that allows a portion of the movable roller to protrude, and is connected to the internal space. The second opening may be wider than the first opening and be connected to the internal space so as to allow the removal of dust that enters the internal space through the first opening.

[0148] According to the above-mentioned structure, when the movable part is placed in the submerged position, the first opening of the movable part is exposed from the opening recess in a state where the movable part faces the ground. At this time, a part of the movable roller protrudes through the first opening. Therefore, when the suction nozzle is in a grounded state in contact with the ground, the movable roller can roll on the ground, and the ground is not easily damaged. When the movable roller rolls on the ground, dust attached to the movable roller may enter the internal space of the movable part through the first opening. In order to easily remove such dust, a second opening wider than the first opening is formed in the movable part. Even if the second opening is wider than the first opening, when the movable part is placed in the submerged position, it is in a state of entering the opening recess, so it is difficult for dust to invade the movable part through the second opening.

[0149] In the above-mentioned structure, an opening recess opening downward may be formed in the nozzle housing. The nozzle may further include: a movable portion, which is mounted on the nozzle housing in a manner that the movable portion is placed in a protruding position protruding from the opening recess when the nozzle is in a separated state with a gap relative to the ground, and is placed in a recessed position from the protruding position to the opening recess when the nozzle is in a grounded state in contact with the ground; and a movable roller, which is held by the movable portion in a manner that the movable roller rolls on the ground when in the grounded state. The ground contact area of ​​the movable roller on the ground may be smaller than the ground contact area of ​​the rear roller on the ground.

[0150] According to the above-mentioned structure, the first rear roller and the second rear roller are bilaterally symmetrical in such a manner that the forces transmitted to the ground in the left and right directions cancel each other out. However, if the movable roller contacts the ground, the force balance will be destroyed. Therefore, the movable roller is configured to contact the ground with a narrower contact area than the first rear roller and the second rear roller, and as a result, the influence of the movable roller on the force balance between the first rear roller and the second rear roller is reduced. Therefore, even if the movable roller contacts the ground, when the user moves the nozzle forward, it is difficult for the nozzle to turn left or right.

[0151] In the above configuration, the nozzle housing may include a partition wall that partitions the rear end of the suction space. The lower portion of the partition wall may be in a forward-leaning posture that moves away from the brush roller as it moves downward.

[0152] The narrower the space around the brush roller, the more miniaturized the suction nozzle can be. Therefore, it is ideal that the partition wall is as close to the brush roller as possible. However, in this case, it is expected that when the brush roller rotates to move the suction nozzle forward, the fluff of the carpet laid on the ground will be sandwiched between the lower part of the partition wall and the brush roller. In order to avoid such a situation, in the above-mentioned structure, the lower part of the partition wall is in a forward-leaning posture away from the brush roller as it goes downward. Therefore, at a position close to the carpet, the space between the brush roller and the partition wall becomes wide, and it is difficult for the fluff of the carpet to be sandwiched between the brush roller and the partition wall.

[0153] Industrial Applicability

[0154] The above-described technology can be advantageously utilized in devices used for cleaning operations.

Claims

1. A nozzle for a suction type vacuum cleaner, characterized in that include: The nozzle housing is formed with a suction space opening downward so that dust on the ground can be sucked in; A driving unit, generating a driving force; The brush roller is rotatably supported by the nozzle housing in a state where it can contact the ground, and is rotated based on the driving force of the driving unit, thereby sweeping dust on the ground and generating a propulsion force to move the nozzle forward; as well as, The rear roller is rotatably mounted on the nozzle housing in such a manner that it rolls on the ground at the rear side relative to the brush roller when the nozzle moves forward; wherein, The brush roller and the rear roller support the nozzle housing so that the lower side surface of the nozzle housing is in a rearwardly inclined posture that is downwardly moved rearward.

2. The nozzle according to claim 1, characterized in that: The vacuum cleaner comprises: a suction pipe having a flow path formed therein for allowing dust sucked through the suction space to flow; The nozzle housing is configured to be connectable to the suction pipe at a position located on the front side with respect to the rear roller and on the rear side with respect to the brush roller.

3. The nozzle according to claim 1 or 2, characterized in that Also includes: The second rear roller is rotatably mounted on the nozzle housing at the left or right side relative to the rear roller, that is, the first rear roller; wherein, The first rear roller is capable of rolling on the ground around a rotating shaft that is inclined in a manner to assist the suction nozzle to move obliquely to the left front or obliquely to the right front. The second rear roller rotates around a rotation axis that is left-right symmetrical to the rotation axis of the first rear roller, and can roll on the ground in a manner to assist the suction nozzle in moving diagonally to the front right or diagonally to the front left.

4. The nozzle according to claim 1, characterized in that: The vacuum cleaner comprises: a suction pipe having a flow path formed therein for allowing dust sucked through the suction space to flow; The nozzle also includes: The second rear roller is rotatably mounted on the nozzle housing at the left or right side relative to the rear roller, that is, the first rear roller; wherein, The first rear roller is capable of rolling on the ground around a rotating shaft that is inclined in a manner to assist the suction nozzle to move obliquely to the left front or obliquely to the right front. The second rear roller rotates around a rotation axis that is symmetrical to the rotation axis of the first rear roller, and can roll on the ground in a manner to assist the suction nozzle to move diagonally to the right front or diagonally to the left front. The nozzle housing includes a connection portion configured to be connectable to the suction pipe at a rear side relative to the brush roller. The connection portion is provided at a position located on the front side with respect to the first rear roller and the second rear roller and at a position separated from the first rear roller and the second rear roller by the same distance.

5. The nozzle according to claim 4, characterized in that: The nozzle housing has: a central portion, provided with the connecting portion; a left portion, extending from the central portion to the left; and a right portion, extending from the central portion to the right. The first rear roller and the second rear roller are mounted on the central portion in such a manner that the left portion and the right portion are off the ground, thereby allowing the nozzle housing to tilt based on the left-right tilting of the suction pipe when the suction pipe tilts left-right. Of the first rear roller and the second rear roller, the roller on the left side can roll on the ground around a rotating shaft inclined in a manner to assist the suction nozzle to move diagonally to the left and front, and the roller on the right side can roll on the ground around a rotating shaft inclined in a manner to assist the suction nozzle to move diagonally to the right and front.

6. The nozzle according to claim 5, characterized in that Also includes: The second brush roller is disposed in the suction space symmetrically with the brush roller, that is, the first brush roller, and is rotatably supported by the nozzle housing in a state of being able to contact the ground, and is rotationally driven based on the driving unit; wherein, Of the first brush roller and the second brush roller, the brush roller located on the left side rotates around the rotating shaft inclined in such a manner as to generate a propulsion force in the direction of moving the suction nozzle obliquely to the left front when driven by the driving unit, and the brush roller located on the right side rotates around the rotating shaft inclined in such a manner as to generate a propulsion force in the direction of moving the suction nozzle obliquely to the right front when driven by the driving unit.

7. The nozzle according to claim 5, characterized in that Also includes: The second brush roller is disposed in the suction space symmetrically with the brush roller, that is, the first brush roller, and is rotatably supported by the nozzle housing in a state of being able to contact the ground, and is rotationally driven based on the driving unit; wherein, The first brush roller and the second brush roller each include: a roller body extending in the left-right direction; and a brush row protruding from an outer peripheral surface of the roller body. Among the first brush roller and the second brush roller, the brush row of the brush roller located on the left side is extended in such a manner that when driven by the driving unit, the brush row contacts the ground and generates a propulsion force in the direction of moving the suction nozzle diagonally forward to the left, and the brush row of the brush roller located on the right side is extended in such a manner that when driven by the driving unit, the brush row contacts the ground and generates a propulsion force in the direction of moving the suction nozzle diagonally forward to the right.

8. The nozzle according to claim 5 or 6, characterized in that Also includes: a left auxiliary roller mounted on the left portion in a manner rotatable about a rotation axis extending in the left-right direction; as well as, The right auxiliary roller is mounted on the right portion in a manner rotatable around a rotation axis extending in the left-right direction; wherein, The left auxiliary roller and the right auxiliary roller are suspended relative to the ground when the nozzle housing is not tilted in the left-right direction. The left auxiliary roller contacts the ground when the nozzle housing tilts to the left by a specified angle. The right auxiliary roller contacts the ground when the nozzle housing is tilted to the right by a specified angle.

9. The nozzle according to claim 1 or 2, characterized in that: A accommodating recessed portion opening downward is formed in the nozzle housing, and the accommodating recessed portion can accommodate the rear roller in a state where a portion of the rear roller protrudes from the lower side surface of the nozzle housing. The nozzle also includes: a roller shaft, rotatably supporting the rear roller in the receiving recess; and A stopper restricts displacement of the rear roller by a predetermined amount or more in the axial direction of the roller shaft; wherein: The stopper is provided on the upper side with respect to the roller shaft.

10. The suction nozzle according to claim 9, characterized in that: The stopper is provided in the housing recessed portion in a state of being spaced apart from the roller shaft.

11. The nozzle according to claim 9, characterized in that Also includes: A pair of ring bodies are arranged in a manner to clamp the rear roller in the axial direction of the roller shaft; wherein, The stopper has a pair of stopper plates which are arranged to be spaced apart from the pair of ring bodies and to face the pair of ring bodies. Each of the stopper pieces is configured to restrict displacement of the rear roller in the axial direction of the roller shaft by contacting a ring body facing the stopper piece in a state where the stopper piece is spaced apart from the rear roller.

12. The nozzle according to claim 1 or 2, characterized in that: An opening recessed portion opening downward is formed in the nozzle housing. The nozzle also includes: The movable part is mounted on the nozzle housing in such a manner that when the nozzle is in a separated state with a gap relative to the ground, the movable part is placed in a protruding position protruding from the opening recessed part, and when the nozzle is in a grounded state with a gap relative to the ground, the movable part is placed in a retracted position retracted from the protruding position into the opening recessed part; a position detection unit for detecting whether the movable unit is located at the sunken position; and The drive control unit operates the drive unit on the condition that the position detection unit detects that the movable unit is located at the retracted position.

13. The nozzle according to claim 12, characterized in that Also includes: The movable roller is held by the movable part in such a manner that the movable roller rolls on the ground in the ground contact state; wherein, The movable part is formed with: an internal space for accommodating the movable roller; a first opening for exposing the movable part from the opening recessed portion in a state where the movable part faces the ground when the movable part is placed in the submerged position; and a second opening, wherein the movable portion is inserted into the opening recess when the movable portion is in the retracted position, and the movable portion is exposed from the opening recess when the movable portion is in the protruding position. The first opening has a size that allows a portion of the movable roller to protrude, and is communicated with the internal space. The second opening is wider than the first opening and communicates with the internal space so as to allow removal of dust that has entered the internal space through the first opening.

14. The nozzle according to claim 3, characterized in that: An opening recessed portion opening downward is formed in the nozzle housing. The nozzle also includes: The movable part is mounted on the nozzle housing in such a manner that when the nozzle is in a separated state with a gap relative to the ground, the movable part is placed in a protruding position protruding from the opening recessed part, and when the nozzle is in a grounded state with a gap relative to the ground, the movable part is placed in a retracted position retracted from the protruding position into the opening recessed part; The movable roller is held by the movable part in such a manner that the movable roller rolls on the ground in the ground contact state; wherein, The contact area of ​​the movable roller with the ground is smaller than the contact area of ​​the rear roller with the ground.

15. The nozzle according to claim 1 or 2, characterized in that: The nozzle housing has a partition wall that divides the rear end of the suction space. The lower portion of the partition wall is in a forward-leaning posture that moves away from the brush roller as it goes downward.

Images