Suction nozzle and vacuum cleaner

Abstract

To provide a suction port body that comprises a rotary brush normally rotating in a preceding manner and a rotary brush reversely rotating in a following manner and that can achieve both of frisky moving performance and dust removing performance adaptable to a variety of surfaces to be cleaned, and a vacuum cleaner.SOLUTION: A suction port body 16 determines in which direction crossing a rotation center line a rotary cleaning body 28 is traveling, based on a current value or a change in current flowing through an electric motor for rotary driving of at least one of the rotary cleaning bodies, as detected by a current detection circuit 98. A plurality of electric motors 29 are operated so that an auxiliary force generated in the traveling direction by the normally rotating rotary cleaning body becomes greater than a resistance force generated in the opposite direction to the traveling direction by the reversely rotating rotary cleaning body.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] Embodiments according to the present invention relate to a suction port body and a vacuum cleaner.

Background Art

[0002] There is known a suction port body including two rotary brushes and two electric motors that independently rotate and drive the two rotary brushes.

[0003] The two rotary brushes have a rotation center line extending in the width direction of the suction port body and are arranged in front of and behind the suction port body. The two rotary brushes sandwich the suction port. When the suction port body moves in the front-rear direction, the leading rotary brush rotates to assist the running of the suction port body, scrapes up the dust on the cleaning surface toward the rear, and guides it to the suction port; the trailing rotary brush rotates to resist the running of the suction port body, scrapes up the dust on the cleaning surface toward the front, and guides it to the suction port.

[0004] For the convenience of the following description, the rotation of the rotary brush that precedes and assists the running of the suction port body is called the leading forward rotation, and the rotation of the rotary brush that trails and resists the running of the suction port body is called the trailing reverse rotation.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The load on the electric motor that rotates the rotating brush depends on the rolling resistance between the rotating brush and the surface being cleaned. In environments where household vacuum cleaners are typically used, there is a mixture of surfaces with different properties. Typical examples of surfaces with different properties include smooth surfaces with low rolling resistance, such as wooden floors and hardwood floors, and surfaces with high rolling resistance, such as carpets. Furthermore, surfaces like carpets have a grain direction, known as the forward and reverse directions of the fabric's weave. The rolling resistance between the forward grain of the carpet and the rotating brush may also differ from the rolling resistance between the reverse grain of the carpet and the rotating brush. In other words, the rolling resistance between the rotating brush and the surface being cleaned in environments where household vacuum cleaners are typically used varies greatly depending on the properties of the surface being cleaned.

[0007] Conventional suction nozzles are equipped with a rotating brush that rotates in the forward direction and a rotating brush that rotates in the backward direction. In such conventional suction nozzles, if the contact state between the rotating brush and the surface to be cleaned is set with an emphasis on smooth surfaces to be cleaned, such as wooden floors or hardwood floors, then on surfaces with high rolling resistance, such as carpets, there is a possibility that stop control, i.e., safety control, will be frequently executed to avoid overloading the motor. In addition, in suction nozzles that rotate multiple rotating brushes with a single motor, the load borne by the single motor increases. This increase in load increases the likelihood that safety control will be executed to avoid overloading.

[0008] Furthermore, in conventional suction nozzles, if the contact between the rotating brush and the surface being cleaned is set prioritizing surfaces with high rolling resistance, such as carpets, then contact between the rotating brush and smooth surfaces such as wooden floors or hardwood floors will be insufficient, resulting in reduced dust collection performance. Moreover, the relative magnitudes of the thrust acting on the surface being cleaned from the forward-rotating brush and the thrust acting on the surface being cleaned from the backward-rotating brush greatly affect the comfort of operating the suction nozzle. For example, if these thrusts are balanced, they cancel each other out and do not contribute to either the forward or backward operation of the suction nozzle.

[0009] Therefore, the present invention aims to propose a suction nozzle and a vacuum cleaner that are equipped with a rotating brush that rotates forward and a rotating brush that rotates backward, and that can achieve both smooth movement and dust collection performance to accommodate various surfaces to be cleaned. [Means for solving the problem]

[0010] To solve the aforementioned problems, an embodiment of the present invention provides a suction port body comprising: a plurality of rotating cleaning bodies having parallel rotational centerlines; a plurality of electric motors that generate rotational driving force for the plurality of rotating cleaning bodies; a current detection circuit that individually detects the current flowing through each of the electric motors; and a control unit that controls the operation of the plurality of electric motors. The control unit determines, based on the detection result of the current detection circuit, which direction the plurality of rotating cleaning bodies are moving in intersecting the rotational centerlines; operates at least one of the electric motors so that the leading rotating cleaning body rotates in the forward rotation direction to assist its movement; and operates the other electric motors so that at least one of the rotating cleaning bodies following the leading rotating cleaning body rotates in the reverse rotation direction. The system operates at least one of the motors, and the multiple motors are operated such that the auxiliary force generated by the forward-rotating cleaning body in the direction of travel is greater than the resistance force generated by the reverse-rotating cleaning body in the opposite direction of travel. Based on the interval at which peak currents occur in which the current value flowing through at least one of the multiple motors exceeds a predetermined determination current, the system estimates the time interval in which the multiple rotating cleaning bodies move in a direction intersecting the rotation centerline. If the estimated time interval is shorter than a predetermined time interval, the difference between the auxiliary force and the resistance force is set as the first difference. If the estimated time interval is greater than or equal to the predetermined time interval, the difference between the auxiliary force and the resistance force is set as the second difference, which is greater than the first difference.

[0011] Furthermore, the suction port body according to the embodiment of the present invention comprises a plurality of rotating cleaning bodies having parallel rotational centerlines, a plurality of electric motors that generate rotational driving force for the plurality of rotating cleaning bodies, a current detection circuit that individually detects the current flowing through each of the electric motors, and a control unit that controls the operation of the plurality of electric motors, wherein the control unit determines, based on the detection result of the current detection circuit, which direction the plurality of rotating cleaning bodies are moving in intersecting the rotational centerlines, operates at least one of the electric motors so that the rotating cleaning body leading in the direction of travel rotates in the forward rotation direction to assist its movement, operates at least one other electric motor so that at least one of the rotating cleaning bodies following the leading rotating cleaning body rotates in the reverse rotation direction, and the assisting force generated by the forward-rotating rotating cleaning body in the direction of travel is before the reverse rotation. The plurality of electric motors are operated so that the resistance force generated by the rotating cleaning body in the opposite direction of travel is greater than the resistance force generated by the rotating cleaning body in the opposite direction of travel. Based on the current value flowing through the electric motor that rotates at least one of the rotating cleaning bodies rotating in the forward direction, or the change in the current value flowing through the electric motor that rotates at least one of the rotating cleaning bodies rotating in the forward direction, a change in the direction of travel is detected and it is determined which direction the plurality of rotating cleaning bodies are moving in that intersects the rotation centerline. Based on the degree to which the rotating cleaning body is pressed against the surface to be cleaned, which is reflected in the length of the duration of the peak current where the current value flowing through the electric motor that rotates at least one of the rotating cleaning bodies rotating in the forward direction exceeds a predetermined determination current, a change in the direction of travel is detected and it is determined which direction the plurality of rotating cleaning bodies are moving in that intersects the rotation centerline.

[0012] Furthermore, an electric vacuum cleaner according to an embodiment of the present invention comprises a vacuum cleaner body, an electric blower housed in the vacuum cleaner body that generates negative pressure, and a suction port body that is fluidly connected to the electric blower.

[0013] Furthermore, an electric vacuum cleaner according to one embodiment of the present invention comprises a plurality of rotating cleaning bodies having parallel rotational centerlines, a plurality of electric motors that generate rotational driving force for the plurality of rotating cleaning bodies, a current detection circuit that individually detects the current flowing through each of the electric motors, and a control unit that controls the operation of the plurality of electric motors, wherein the control unit determines, based on the detection result of the current detection circuit, which direction the plurality of rotating cleaning bodies are moving in intersecting the rotational centerlines, and operates at least one of the electric motors so that the rotating cleaning body leading in the direction of movement rotates in the forward rotation direction to assist its movement, and operates at least one of the electric motors so that the rotating cleaning body following the leading rotating cleaning body rotates in the reverse rotation direction. The system operates at least one of the motors, and the multiple motors are operated such that the auxiliary force generated by the forward-rotating cleaning body in the direction of travel is greater than the resistance force generated by the reverse-rotating cleaning body in the opposite direction of travel. Based on the interval at which peak currents occur in which the current value flowing through at least one of the multiple motors exceeds a predetermined determination current, the system estimates the time interval in which the multiple rotating cleaning bodies move in a direction intersecting the rotation centerline. If the estimated time interval is shorter than a predetermined time interval, the difference between the auxiliary force and the resistance force is set as the first difference. If the estimated time interval is greater than or equal to the predetermined time interval, the difference between the auxiliary force and the resistance force is set as the second difference, which is greater than the first difference.

[0014] Furthermore, an electric vacuum cleaner according to another embodiment of the present invention comprises a plurality of rotating cleaning bodies having parallel rotational centerlines, a plurality of electric motors that generate rotational driving force for the plurality of rotating cleaning bodies, a current detection circuit that individually detects the current flowing through each of the electric motors, and a control unit that controls the operation of the plurality of electric motors, wherein the control unit determines, based on the detection result of the current detection circuit, which direction the plurality of rotating cleaning bodies are moving in intersecting the rotational centerlines, operates at least one of the electric motors so that the rotating cleaning body leading in the direction of travel rotates in a forward rotation direction that assists its movement, operates at least one other electric motor so that at least one of the rotating cleaning bodies following the leading rotating cleaning body rotates in a reverse rotation direction, and the assisting force generated by the forward-rotating rotating cleaning body in the direction of travel is such that the reverse rotation The plurality of electric motors are operated so that the resistance force generated by the rotating cleaning body in the opposite direction of travel is greater than the resistance force generated by the rotating cleaning body in the opposite direction of travel. Based on the current value flowing through the electric motor that rotates at least one of the rotating cleaning bodies that rotates in the forward direction, or the change in the current value flowing through the electric motor that rotates at least one of the rotating cleaning bodies that rotates in the forward direction, a change in the direction of travel is detected and it is determined which direction the plurality of rotating cleaning bodies are moving in that intersects the rotation centerline. Based on the degree to which the rotating cleaning body is pressed against the surface to be cleaned, which is reflected in the length of the duration of the peak current in which the current value flowing through the electric motor that rotates at least one of the rotating cleaning bodies that rotates in the forward direction exceeds a predetermined determination current, a change in the direction of travel is detected and it is determined which direction the plurality of rotating cleaning bodies are moving in that intersects the rotation centerline. [Brief explanation of the drawing]

[0015] [Figure 1] A perspective view of a vacuum cleaner according to an embodiment of the present invention. [Figure 2] A perspective view showing the suction port body from the front right according to an embodiment of the present invention. [Figure 3] A plan view of a suction port body according to an embodiment of the present invention. [Figure 4] A plan view of a suction port body according to an embodiment of the present invention. [Figure 5]Bottom view of the suction inlet body according to an embodiment of the present invention. [Figure 6] Perspective view of the suction inlet body according to an embodiment of the present invention, viewed from below. [Figure 7] Longitudinal sectional view of the suction inlet body according to an embodiment of the present invention. [Figure 8] Longitudinal sectional view of the suction inlet body according to an embodiment of the present invention. [Figure 9] Partial sectional view of the suction inlet body according to an embodiment of the present invention. [Figure 10] Partial sectional view of another example of the suction inlet body according to an embodiment of the present invention. [Figure 11] Control block diagram of the suction inlet body according to an embodiment of the present invention. [Figure 12] Graph of an example of the current flowing through the motor for forward drive and the motor for backward drive of the suction inlet body according to an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0016] Embodiments of the suction inlet body and the vacuum cleaner according to the present invention will be described with reference to FIGS. 1 to 12.

[0017]

[0018] As shown in FIG. 1, the vacuum cleaner 1 according to the present embodiment is, for example, a stick type. The vacuum cleaner 1 includes a cleaner main body 12 having a handle 11 and being operable by hand, a secondary battery 13 detachably attached to the cleaner main body 12, an extension tube 15 connected to the cleaner main body 12, and a suction inlet body 16 connected to the extension tube 15. <*

[0019] The vacuum cleaner 1 may be a canister type, an upright type, or a handy type. The vacuum cleaner 1 may be a cordless type that uses the secondary battery 13 as a power source, or a wired type that obtains power from a commercial AC power source via a power cord.

[0020] The vacuum cleaner body 12 comprises a main body case 17 having a handle 11, an electric blower 18 housed in the main body case 17 that generates suction negative pressure, a dust separation and collection unit 19 detachably provided in the main body case 17, and a main body control unit 21 that mainly controls the electric blower 18.

[0021] The vacuum cleaner body 12 drives the electric blower 18 using the power stored in the secondary battery 13. The negative pressure generated by the operation of the electric blower 18 acts on the suction port 16 via the dust separation and collection unit 19 and the extension pipe 15. The electric vacuum cleaner 1 sucks in dust-containing air (hereinafter referred to as "dust-containing air") from the floor surface through the suction port 16 and the extension pipe 15, separates the dust from the dust-containing air, collects and stores the separated dust, and exhausts the air after separation.

[0022] The main body case 17 comprises a cylindrical front section 17a positioned on the extension line of the extension pipe 15 in a side view, and a rear section 17b that bends from the front section 17a and gradually moves away from the extension line of the extension pipe 15. A dust separation and collection section 19 is provided above the front section 17a of the main body case 17. The rear section 17b of the main body case 17 extends towards the rear in the operating state with the suction port 16 placed on the floor (Figure 2).

[0023] The front portion of the main unit case 17 has a main unit connection port 23.

[0024] The main unit connection port 23 is a fitting to which the extension pipe 15 can be attached and detached. The main unit connection port 23 protrudes forward from the cylindrical front half portion 17a of the main unit case 17. The main unit connection port 23 is the fluid inlet of the vacuum cleaner body 12 and fluidly connects the extension pipe 15 to the dust separation and dust collection unit 19. By removing the extension pipe 15 from the vacuum cleaner body 12, the main unit connection port 23 also functions as a suction port when the vacuum cleaner body 12 is used alone.

[0025] The handle 11 is integrally attached to the main body case 17. The handle 11 is the part that the user grips with their hand when cleaning the floor with the vacuum cleaner 1. The handle 11 arches over the rear end of the main body case 17, near the rear end of the dust separation and collection unit 19. The handle 11 is also positioned to intersect with the extension of the center line of the extension pipe 15.

[0026] An input unit 26 is provided near the handle 11, positioned within the range of movement of the user's fingers while holding the handle 11.

[0027] The input unit 26 includes an operation start switch 26a that receives an operation to start the electric blower 18, an operation stop switch 26b that receives an operation to stop the electric blower 18, and a brush switch 26c that receives an operation to start and stop the power supply to the suction port 16. The operation start switch 26a and the operation stop switch 26b are electrically connected to the main unit control unit 21. The user of the vacuum cleaner 1 can selectively select the operating mode of the electric blower 18 by operating the input unit 26. The operation start switch 26a also functions as an operating mode changeover switch while the electric blower 18 is in operation. In this case, the main unit control unit 21 switches the operating mode in the order of strong → medium → weak → strong → medium → weak →... each time it receives an operation signal from the operation start switch 26a. The input unit 26 may also be equipped with a strong operation switch (not shown), a medium operation switch (not shown), and a weak operation switch (not shown) separately instead of the operation start switch 26a.

[0028] The dust separation and collection unit 19 is located on the upper side of the vacuum cleaner body 12 and is detachable from the vacuum cleaner body 12. The dust separation and collection unit 19 separates, collects, and stores dust from the dust-laden air flowing into the vacuum cleaner body 12, while simultaneously sending the clean air from which the dust has been removed to the electric blower 18. The dust separation and collection unit 19 may be a centrifugal separation system that uses the difference in mass between the dust and air sucked in by the electric vacuum cleaner 1 to separate the dust and air by centrifugal force, or it may be a filtration separation system that has a filter to filter out dust from the dust-laden air.

[0029] The electric blower 18 draws air from the dust separation and collection unit 19 to generate negative pressure (suction negative pressure).

[0030] The main control unit 21 includes a microprocessor and a memory device that stores various calculation programs and parameters executed by the microprocessor. The memory device stores various settings (arguments) related to a plurality of pre-set operating modes. The plurality of operating modes are associated with the output of the electric blower 18. Each operating mode has different input values ​​set for each other (input value of the electric blower 18, target current value flowing to the electric blower 18). Each operating mode is associated with an operation input received by the input unit 26. The main control unit 21 selectively selects an arbitrary operating mode corresponding to the operation input to the input unit 26 from the plurality of pre-set operating modes. The main control unit 21 also reads the settings of the selected operating mode from the memory device and operates the electric blower 18 according to the settings of the read operating mode.

[0031] The secondary battery 13 is also called a storage battery, rechargeable battery, or rechargeable rechargeable battery. The secondary battery 13 stores the power consumed by the electric blower 18 and the main unit control unit 21. The secondary battery 13 may be fixed to the main unit case 17, or it may be detachable from the main unit case 17. In other words, the vacuum cleaner 1 may or may not be able to use multiple secondary batteries 13 as needed. If the charge level of a secondary battery 13 that is detachably installed in the vacuum cleaner 1 decreases, the operation of the vacuum cleaner 1 can be continued by replacing this secondary battery 13 with a fully charged secondary battery 13.

[0032] The extension pipe 15 and the suction port body 16, by the negative pressure acting from the electric blower 18, suck up dust from the floor surface along with air and guide it to the vacuum cleaner body 12.

[0033] The extension tube 15 is fluidly connected to the suction side of the electric blower 18 via the main body connection port 23 and dust separation and collection section 19 of the main body case 17. The extension tube 15 is long enough to substantially reach the floor when the user is holding the handle 11 of the vacuum cleaner body 12. One end of the extension tube 15 is provided with a joint structure that can be attached to the main body connection port 23 of the vacuum cleaner body 12. The other end of the extension tube 15 is provided with a joint structure that can be attached to the suction port 16 of the vacuum cleaner body 12. The extension tube 15 may or may not be extendable.

[0034] The suction port body 16 is capable of freely traveling or sliding on a floor surface with its bottom surface facing the floor surface, such as a wooden floor or carpet. The bottom surface of the suction port body 16 has a suction port 27. The suction port body 16 also includes a rotatable rotating cleaning body 28 and an electric motor 29 as a drive source for driving the rotating cleaning body 28. One end of the suction port body 16 is provided with a joint structure that can be attached to the other end of the extension pipe 15. The suction port body 16 is fluidly connected to the suction side of the electric blower 18 via the extension pipe 15. The suction port body 16, the extension pipe 15, and the dust separation and collection unit 19 form a suction air passage from the electric blower 18 to the suction port 27.

[0035] When the start switch 26a of the vacuum cleaner 1 is operated, the electric blower 18 is started. For example, when the start switch 26a of the vacuum cleaner 1 is operated while the electric blower 18 is stopped, the electric blower 18 is first started in high-power mode, then when the start switch 26a is operated again, the operating mode of the electric blower 18 is changed to medium mode, and when the start switch 26a is operated a third time, the operating mode of the electric blower 18 is changed to low-power mode, and so on. High-power mode, medium mode, and low-power mode are multiple pre-set operating modes. The input value of the electric blower 18 is highest in high-power mode and lowest in low-power mode. When the electric blower 18 is started, it draws air from the dust separation and collection unit 19 and creates negative pressure inside the dust separation and collection unit 19.

[0036] The negative pressure inside the dust separation and collection unit 19 acts on the suction port 27 through the main unit connection port 23, extension pipe 15, and suction port body 16 in sequence. The vacuum cleaner 1 uses the negative pressure acting on the suction port 27 to suck up dust from the surface to be cleaned along with air, cleaning the surface. The dust separation and collection unit 19 separates and stores dust from the dust-containing air sucked into the vacuum cleaner 1, while sending the air separated from the dust-containing air to the electric blower 18. The electric blower 18 exhausts the air sucked in from the dust separation and collection unit 19 to the outside of the vacuum cleaner body 12.

[0037] Next, the suction port body 16 will be described in detail.

[0038] Figure 2 is a perspective view showing the suction port body according to an embodiment of the present invention from the front right.

[0039] As shown in Figure 2, the suction port body 16 according to this embodiment comprises a substantially rectangular parallelepiped suction port body 31 and a connecting pipe 32 provided at the rear of the suction port body 31.

[0040] The front, back, left, right, and up and down directions of the suction port 16 are explained from the perspective of the user of the vacuum cleaner 1. The direction of the solid arrow X in Figure 2 is the front or forward direction of the suction port 16, and the opposite direction is the rear or backward direction. Also, the direction of the solid arrow Y in Figure 2 is the left side of the suction port 16, and the opposite direction is the right side. Furthermore, the direction of the solid arrow Z in Figure 2 is the upward direction of the suction port 16, and the opposite direction is downward.

[0041] In plan view, the shape of the suction port body 31 is rectangular, with a shorter side in the front-to-back direction and a longer side in the left-to-right direction. In other words, the left-to-right dimension of the suction port body 31, i.e., the width dimension, is greater than the front-to-back dimension of the suction port body 31, i.e., the depth dimension. The suction port body 31 comprises a lower case 35 and an upper case 36 that covers the lower case 35.

[0042] The connecting pipe 32 is located at the rear of the suction port body 31, approximately in the center in the width direction. The connecting pipe 32 is a so-called universal joint. The connecting pipe 32 comprises a rotating connecting pipe 38 that is rotatable relative to the suction port body 31, and a swinging connecting pipe 39 that is swingable relative to the rotating connecting pipe 38.

[0043] The rotating connecting pipe 38 rotates around a center line (a line segment that coincides with the X-axis or is parallel to the X-axis) that extends in the front-to-back direction of the suction port body 16. This center line divides the suction port body 31 into left and right halves.

[0044] The oscillating connecting pipe 39 oscillates around a line segment perpendicular to the rotational centerline of the rotating connecting pipe 38, or a line segment parallel to the line segment perpendicular to the rotational centerline of the rotating connecting pipe 38. The free end of the oscillating connecting pipe 39 is a joint that can be attached to the free end of the extension pipe 15.

[0045] Figures 3 and 4 are plan views of the suction port body according to an embodiment of the present invention.

[0046] Figure 5 is a bottom view of the suction port body according to an embodiment of the present invention.

[0047] Figure 6 is a perspective view of the suction port body according to an embodiment of the present invention, viewed from below.

[0048] Figure 7 is a longitudinal cross-sectional view of the suction port body according to an embodiment of the present invention, along the line VII-VII in Figure 3.

[0049] Figure 8 is a longitudinal cross-sectional view of the suction port body according to an embodiment of the present invention, along the line VIII-VIII in Figure 3.

[0050] Note that in Figure 4, the upper case 36 has been removed.

[0051] As shown in Figures 3 to 7, the suction port body 16 according to this embodiment includes a suction port body 31, a plurality of rotating cleaning bodies 28 rotatably supported by the suction port body 31, a plurality of electric motors 29 as a drive source for generating rotational driving force for the rotating cleaning bodies 28, a power transmission mechanism 41 for transmitting driving force from each electric motor 29 to the corresponding rotating cleaning body 28, and a suction port body control unit 42 for controlling the operation of the electric motors 29.

[0052] The suction port body 31 has a suction port 27 that opens toward the bottom surface 31a, a suction chamber 45 connected to the suction port 27, and a cleaning chamber 46 for housing the rotating cleaning body 28.

[0053] Furthermore, the suction port body 31 is equipped with a permeable wall 47 that partitions a portion of the cleaning chamber 46 and visually covers at least a portion of the outer surface of the rotating cleaning body 28.

[0054] The cleaning chamber 46 is partitioned off to the outside of the suction chamber 45. The cleaning chamber 46 is open toward the bottom surface 31a of the suction port body 31.

[0055] The intake chamber 45 is partitioned by the lower case 35, the air passage cover 48 which is housed inside the upper case 36 and covers a part of the lower case 35, and the air passage constriction body 49 which narrows the wide intake port 27 of the intake port body 31 toward the center. In other words, the lower case 35, the air passage cover 48, and the air passage constriction body 49 work together to partition the intake chamber 45.

[0056] The suction port body 31 is provided with a plurality of rollers 50 that make contact with the surface to be cleaned f and support the suction port body 31. The plurality of rollers 50 are arranged on the bottom surface 31a of the suction port body 31. The plurality of rollers 50 include rollers 50 arranged at the left and right ends of the suction port body 31 and rollers 50 arranged at the rear center of the suction port body 31.

[0057] A space is partitioned between the lower case 35 and the upper case 36 of the suction port body 31. This space includes a motor room 51 housing the electric motor 29, a machine room 52 housing the power transmission mechanism 41, and a control room 53 housing the suction port body control unit 42. These motor room 51, machine room 52, and control room 53 may be connected or separated.

[0058] In a plan view, the control room 53 is located in the center of the front, back, left, and right sides of the intake port body 31.

[0059] The multiple rotating cleaning bodies 28 have parallel rotational centerlines. In other words, the rotational centerlines of the multiple rotating cleaning bodies 28 extend in the left-right direction of the suction port body 31. The multiple rotating cleaning bodies 28 include a pair of rotating cleaning bodies 28 that sandwich the suction port 27 from the front and rear of the suction port 27.

[0060] There are also pairs of electric motors 29 and power transmission mechanisms 41, each corresponding individually to a rotating cleaning body 28. One electric motor 29 rotates one rotating cleaning body 28 via one power transmission mechanism 41. The other electric motor 29 rotates the other rotating cleaning body 28 via the other power transmission mechanism 41.

[0061] The pair of electric motors 29 includes an electric motor 29 provided at one end of the suction port body 31 in the width direction and an electric motor 29 provided at the other end of the suction port body 31 in the width direction. It is preferable that these pair of electric motors 29 are positioned at substantially equal distances from the center line that divides the suction port body 31 into left and right halves. Doing so ensures that the rotational balance of the suction port body 31 around the universal joint, i.e., the connecting pipe 32, is uniform, improving handling.

[0062] The pair of power transmission mechanisms 41 includes a power transmission mechanism 41 provided at one end of the suction port body 31 in the width direction, and a power transmission mechanism 41 provided at the other end of the suction port body 31 in the width direction. It is preferable that these pair of power transmission mechanisms 41 are positioned at substantially equal distances from the center line that divides the suction port body 31 into left and right halves. This ensures that the rotational balance of the suction port body 31 around the universal joint, i.e., the connecting pipe 32, is uniform, improving handling.

[0063] The rotating cleaning body 28 located in front of the suction port 27 is called the front cleaning body 28F (first rotating cleaning body). The cleaning body chamber 46 that houses the front cleaning body 28F is called the front cleaning body chamber 46F (first rotating cleaning body chamber). The electric motor 29 corresponding to the front cleaning body 28F is called the front electric motor 29F, and the power transmission mechanism 41 corresponding to the front cleaning body 28F is called the front transmission mechanism 41F. The motor chamber 51 that houses the front electric motor 29F is called the front electric motor chamber 51F, and the machine chamber 52 that houses the front transmission mechanism 41F is called the front machine chamber 52F.

[0064] The rotating cleaning body 28 located behind the suction port 27 is called the rear cleaning body 28R (second rotating cleaning body). The cleaning body chamber 46 that houses the rear cleaning body 28R is called the rear cleaning body chamber 46R (second rotating cleaning body chamber). The electric motor 29 corresponding to the rear cleaning body 28R is called the rear electric motor 29R, and the power transmission mechanism 41 corresponding to the rear cleaning body 28R is called the rear transmission mechanism 41R. The motor chamber 51 that houses the rear electric motor 29R is called the rear electric motor chamber 51R, and the machine chamber 52 that houses the rear transmission mechanism 41R is called the rear machine chamber 52R.

[0065] The front cleaning chamber 46F, the suction port 27, and the rear cleaning chamber 46R are aligned in the direction of travel of the suction port body 16. In other words, the front cleaning body 28F, the suction port 27, and the rear cleaning body 28R are aligned in the direction of travel of the suction port body 16. The front cleaning body 28F, the suction port 27, and the rear cleaning body 28R are aligned from the front to the rear of the suction port body 16. Furthermore, the front cleaning body 28F, the air passage constrictor 49, and the rear cleaning body 28R are aligned in the direction of travel of the suction port body 16. The front cleaning chamber 46F, the suction port 27, and the rear cleaning chamber 46R have substantially the same width.

[0066] When the suction port body 16 is moving forward, the front cleaning chamber 46F and front cleaning body 28F move forward ahead of the rear cleaning chamber 46R and rear cleaning body 28R, and the rear cleaning chamber 46R and rear cleaning body 28R follow behind the front cleaning chamber 46F and front cleaning body 28F and move forward in reverse. When the suction port body 16 is moving backward, the rear cleaning chamber 46R and rear cleaning body 28R move backward ahead of the front cleaning chamber 46F and front cleaning body 28F, and the front cleaning chamber 46F and front cleaning body 28F follow behind the rear cleaning chamber 46R and rear cleaning body 28R and move backward in reverse.

[0067] The electric motor 29 rotates the cleaning body 28 in a direction that sweeps the dust from the surface to be cleaned f towards the suction port 27, with the suction port body 31 positioned on the surface to be cleaned f. In other words, the front electric motor 29F rotates the front cleaning body 28F in a rotational direction Rf that assists the forward movement of the suction port body 16, and the rear electric motor 29R rotates the rear cleaning body 28R in a rotational direction Rr that assists the backward movement of the suction port body 16.

[0068] Hereinafter, when the suction port 16 is moving forward, the rotation of the front cleaning body 28F in the rotational direction Rf that assists the forward movement will be called forward rotation, and the rotation of the rear cleaning body 28R in the rotational direction Rr will be called backward rotation. When the suction port 16 is moving backward, the rotation of the rear cleaning body 28R in the rotational direction Rr that assists the backward movement is also forward rotation, and the rotation of the front cleaning body 28F in the rotational direction Rf is also backward rotation.

[0069] Furthermore, the propulsive force Ff acting on the surface to be cleaned f from the rotating cleaning body 28 that is rotating in the forward direction is called the auxiliary force, and the propulsive force Fr acting on the surface to be cleaned f from the rotating cleaning body 28 that is rotating in the reverse direction behind is called the resistance force.

[0070] The auxiliary force acts in front of the suction port 16 if the suction port 16 is moving forward, and acts behind the suction port 16 if the suction port 16 is moving backward. The resistance force acts behind the suction port 16 if the suction port 16 is moving forward, and acts in front of the suction port 16 if the suction port 16 is moving backward.

[0071] The permeable wall 47 partitions a portion of each cleaning chamber 46 and visually covers at least a portion of the outer surface of each rotating cleaning body 28. Therefore, the suction port body 31 has at least one window portion 55 that is closed by the permeable wall 47. This window portion 55 may be provided in each cleaning chamber 46, or it may span multiple adjacent cleaning chambers 46. The window portion 55 in this embodiment includes a front cleaning body window 55F provided in the upper case 36 so that the front cleaning body 28F can be visually viewed, and a rear cleaning body window 55R provided in the lower case 35 so that the rear cleaning body 28R can be visually viewed.

[0072] The front cleaning unit window 55F is located above the front cleaning unit 28F and is open along the entire length of the front cleaning unit 28F.

[0073] The rear cleaning window 55R is located above the rear cleaning body 28R and is divided into two sections, left and right, on the left and right sides of the rear cleaning body 28R, in order to avoid the suction chamber 45 which passes above the rear cleaning body chamber 46R and leads to the connecting pipe 32. In other words, the rear cleaning window 55R includes multiple divided windows 55RL, 55RR which are divided in a direction along the rotational centerline of the rear cleaning body 28R.

[0074] The permeable wall 47 includes a first permeable wall 47A that blocks the front cleaning body window 55F and covers the front cleaning body window 55F so that it can be seen, and a second permeable wall 47B that blocks the rear cleaning body window 55R and covers the rear cleaning body window 55R so that it can be seen. The second permeable wall 47B may also be divided in a direction along the rotational centerline of the rear cleaning body 28R. In other words, the second permeable wall 47B may include a plurality of divided permeable walls 47BL, 47BR that are divided in a direction along the rotational centerline of the rear cleaning body 28R. To put it another way, at least one permeable wall 47 includes a plurality of divided permeable walls 47BL, 47BR that are divided in a direction along the rotational centerline of at least one rotating cleaning body 28.

[0075] The first permeable wall 47A is fixed to the upper case 36. The first permeable wall 47A extends from the part of the front cleaning body 28F furthest from the surface to be cleaned f, i.e., the top 28Fa, along the rotational direction Rf of the front cleaning body 28F, when the suction port body 31 is positioned on the surface to be cleaned f. The second permeable wall 47B is fixed to the lower case 35. The second permeable wall 47B extends from the part of the rear cleaning body 28R furthest from the surface to be cleaned f, i.e., the top 28Ra, along the rotational direction Rr of the rear cleaning body 28R, when the suction port body 31 is positioned on the surface to be cleaned f. In other words, the permeable wall 47 extends from the parts 28Fa and 28Ra furthest from the surface to be cleaned f of the corresponding rotating cleaning body 28, along the rotational direction of the rotating cleaning body 28, when the suction port body 31 is positioned on the surface to be cleaned f.

[0076] The first permeable wall 47A covers the upper part of the front cleaning body 28F and defines the front opening edge of the front cleaning body chamber 46F (the opening edge furthest from the suction port 27). The first permeable wall 47A is a permeable member 56 that also serves as part of the outer shell of the suction port body 31. In other words, the lower case 35, the upper case 36, and the permeable member 56 work together to form the outer shell of the suction port body 31. The permeable member 56 may also be an integrated unit of the first permeable wall 47A and the second permeable wall 47B. In other words, the permeable member 56 may be all or part of the multiple permeable walls 47.

[0077] The permeable member 56 covers the upper case 36, straddles the upper part of the rear cleaning chamber 46R, and is connected to the lower case 35 behind the rear cleaning window 55R. In other words, the permeable member 56 works in cooperation with the second permeable wall 47B to double-cover the rear cleaning window 55R. The permeable member 56 is a molded or shaped product of transparent or translucent resin.

[0078] The suction port 27 is located between the front cleaning chamber 46F and the rear cleaning chamber 46R. In other words, the suction port 27 is located between the front cleaning body 28F and the rear cleaning body 28R. The suction port 27 faces the surface to be cleaned f without being obstructed by the front cleaning body 28F and the rear cleaning body 28R, and directly views the surface to be cleaned f.

[0079] The suction chamber 45 curves behind the suction port body 31 along the lower case 35 so as to overlap the rear cleaning chamber 46R, and is connected to the connecting pipe 32. A relay pipe 57 is provided between the suction chamber 45 and the connecting pipe 32. The relay pipe 57 serves as a base to support the connecting pipe 32. The relay pipe 57 is integrally molded with the air passage cover 48.

[0080] The pre-cleaning chamber 46F is partitioned by the upper case 36, the lower case 35, the first permeable wall 47A of the permeable wall 47, and the air passage constrictor 49. In other words, the upper case 36, the lower case 35, the first permeable wall 47A of the permeable wall 47, and the air passage constrictor 49 work together to partition the pre-cleaning chamber 46F. The pre-cleaning chamber 46F can be seen from the outside of the suction port body 31 through the first permeable wall 47A.

[0081] The post-cleaning chamber 46R is partitioned by the lower case 35, the second permeable wall 47B of the permeable wall 47, and the air passage constrictor 49. In other words, the lower case 35, the second permeable wall 47B of the permeable wall 47, and the air passage constrictor 49 work together to partition the post-cleaning chamber 46R. The post-cleaning chamber 46R can be seen from the outside of the suction port body 31 through the second permeable wall 47B.

[0082] The machine room 52 is located at the left and right ends of the suction port body 31, and is partitioned in the areas where the front cleaning chamber 46F, the suction port 27, and the rear cleaning chamber 46R are absent. The machine room 52 houses the shaft ends of the front cleaning body 28F and the rear cleaning body 28R. A rotating surface 50 is provided at the bottom of the machine room 52.

[0083] The front machine room 52F is located at the left end of the suction port body 31 and is partitioned off in the area where the front cleaning body room 46F, the suction port 27, and the rear cleaning body room 46R are absent. The front machine room 52F houses the shaft end of the front cleaning body 28F and the shaft end of the rear cleaning body 28R.

[0084] The rear machine room 52R is located at the right end of the suction port body 31 and is partitioned off in the area where the front cleaning body room 46F, the suction port 27, and the rear cleaning body room 46R are absent. The rear machine room 52R houses the shaft end of the front cleaning body 28F and the shaft end of the rear cleaning body 28R.

[0085] In a plan view, the motor room 51 overlaps the front cleaning body room 46F, the suction port 27, and the rear cleaning body room 46R, and is located between the control room 53 and the machine room 52. In a side view, the rotational centerlines of the front cleaning body 28F, the rear cleaning body 28R, and the motor 29 are located at the vertices of a triangle. The motor room 51 houses the cylindrical motor 29 as close as possible to the front cleaning body room 46F and the rear cleaning body room 46R. In other words, the bottom of the motor 29 is located below the top 28Fa of the front cleaning body 28F and the top 28Ra of the rear cleaning body 28R. In other words, the electric motor 29 has a portion that is closer to the surface to be cleaned f than the line segment connecting the portion 28Fa of the front cleaning body 28F that is furthest from the surface to be cleaned f of the rear cleaning body 28R that is furthest from the surface to be cleaned f of the rear cleaning body 28R. The arrangement of the electric motor 29 and the configuration of the electric motor room 51 keep the height of the suction port body 31 lower than the sum of the height (diameter) of the rotating cleaning body 28 and the height (diameter) of the electric motor 29, even when the electric motor 29 is positioned above the rotating cleaning body 28.

[0086] The front motor room 51F is located to the left of the suction port body 31 and is adjacent to the front machine room 52F.

[0087] The rear motor room 51R is located to the right of the suction port body 31 and is adjacent to the rear machine room 52R.

[0088] If the front motor room 51F and the front machine room 52F are located side by side, the front motor room 51F and the front machine room 52F may be located to the right of the suction port body 31. In this case, the front transmission mechanism 41F is also located to the right of the suction port body 31. The rear motor room 51R, the rear machine room 52R, and the rear transmission mechanism 41R are located to the left of the suction port body 31.

[0089] The rotational centerline of the rotating cleaning body 28 is oriented in the width direction of the suction port body 31. The rotating cleaning body 28 has radially extending brush bristles 59. The brush bristles 59 are multiple bristles extending in the longitudinal direction of the rotating cleaning body 28 and are arranged in the circumferential direction of the rotating cleaning body 28.

[0090] The rotating cleaning body 28 may be mostly housed in the cleaning body chamber 46, or most of the side portion of the rotating cleaning body 28 may be exposed outside the cleaning body chamber 46. Preferably, the exposed portion of the rotating cleaning body 28 is a part of the front and a part of the back of the suction port body 31.

[0091] The electric motor 29 is equipped with an output shaft 29a that protrudes into the machine room 52. The rotational centerline of the output shaft 29a is substantially parallel to the rotational centerline of the rotating cleaning body 28.

[0092] The power transmission mechanism 41 includes a driving gear 61 fixed to the output shaft 29a of the electric motor 29, a driven gear 62 provided on the rotating cleaning body 28, and an endless belt 63 wrapped around the driving gear 61 and the driven gear 62 to transmit driving force from the electric motor 29 to the rotating cleaning body 28.

[0093] The electric motor 29 and the power transmission mechanism 41 may be housed inside the rotating cleaning body 28, that is, inside the cylindrical shaft portion corresponding to the base of the brush bristles 59.

[0094] The suction port control unit 42 operates the electric motor 29 using power supplied from the vacuum cleaner body 12 via the extension pipe 15.

[0095] The air passage constrictor 49 comprises a partition wall 65 that separates the suction chamber 45 and the cleaning chamber 46, divides the suction chamber 45 and the cleaning chamber 46, and defines a part of the edge of the suction port 27, and a dust removal projection 66 that protrudes from the edge of the partition wall 65 and contacts the rotating cleaning body 28.

[0096] The partition wall 65 that separates the suction chamber 45 and the pre-cleaning chamber 46F is called the front partition wall 65F. The front partition wall 65F defines the front edge of the suction port 27. The dust removal projection 66 that protrudes from the edge of the front partition wall 65F and contacts the pre-cleaning body 28F is called the front projection 66F.

[0097] The partition wall 65 that separates the suction chamber 45 and the rear cleaning chamber 46R is called the rear partition wall 65R. The rear partition wall 65R defines the rear edge of the suction port 27. The dust removal projection 66 that protrudes from the edge of the rear partition wall 65R and contacts the rear cleaning body 28R is called the rear projection 66R.

[0098] A portion of the inner surface of the suction chamber 45 (in this case, the inner surface on the rear side of the suction chamber 45 and the first remaining portion of the inner surface of the suction chamber 45) has a curved surface 68 that faces the front partition wall 65F and is convex toward the front partition wall 65F. The curved surface 68 includes the inner surface of the rear partition wall 65R and the surface of the lower case 35 that is connected to the inner surface of the rear partition wall 65R. The lower case 35 has an arc-shaped wall that partitions a portion of the rear cleaning chamber 46R. This wall has a substantially uniform thickness, concentrically surrounds the rear cleaning body 28R, and smoothly connects to the inner surface of the rear partition wall 65R.

[0099] The dust swept up from the surface to be cleaned f by the rotation of the front cleaning unit 28F is directed towards the curved surface 68 of the suction chamber 45. The curved surface 68 then smoothly guides the incoming dust towards the back (downstream) side of the suction chamber 45.

[0100] Furthermore, a portion of the inner surface of the intake chamber 45 (in this case, the inner surfaces on the left and right sides of the intake chamber 45, and the second remaining portion of the inner surface of the intake chamber 45) is connected to the partition wall 65 and has a funnel-shaped inclined surface 71 that narrows the air passage width toward the rear (downstream) side of the intake chamber 45. The inclined surface 71 is connected to the front partition wall 65F and the rear partition wall 65R. In other words, the inclined surface 71 spans between the front partition wall 65F and the rear partition wall 65R. There is a pair of inclined surfaces 71 on the left and right sides of the air passage constriction body 49. The left and right inclined surfaces 71 move away from the corresponding ends of the air passage constriction body 49 and are inclined so that they move toward the rear side of the intake chamber 45 as they approach the center of the air passage constriction body 49. The left and right inclined surfaces 71 are separated but do not merge. The gap between these left and right inclined surfaces 71 is connected to the intake chamber 45 beyond the inclined surface 71. The inclined surface 71 smoothly guides the air drawn in from the suction port 27, which is elongated in the width direction of the suction port body 16, to the back of the suction chamber 45 connected to the connecting pipe 32.

[0101] The inclined surface 71 has a stepped shape in a vertical cross-sectional view of the suction port body 31, including a guide surface 72 facing the partition wall 65. The guide surface 72 faces the front partition wall 65F. This stepped section may be a single step or multiple steps, as shown in Figure 7. It is preferable that the stepped shape extends to the entire width of the inclined surface 71. The bottom of each step may be flat or recessed. It is preferable that the guide surface 72 is parallel to the front partition wall 65F. The guide surface 72 captures dust swept up by the front cleaning body 28F and guides it to the back of the suction chamber 45. In addition, the guide surface 72 guides the ends of thread-like dust to the back of the suction chamber 45 so that thread-like dust, with one or both ends floating towards the suction port 27, does not cross the rear partition wall 65R and approach the rear cleaning body 28R side.

[0102] The dust removal projection 66 is positioned inside the rotational trajectory of the rotating cleaning body 28. As the rotating cleaning body 28 rotates, the dust removal projection 66 flicks the brush bristles 59 of the rotating cleaning body 28. At this time, the dust removal projection 66 flicks away thread-like dust particles that are attached to the rotating cleaning body 28 and attempting to enter the cleaning chamber 46 from the brush bristles 59, causing them to detach from the rotating cleaning body 28. The thread-like dust particles that have detached from the rotating cleaning body 28 are easily sucked into the suction port 27. In other words, the dust removal projection 66 can prevent thread-like dust particles attached to the rotating cleaning body 28 from entering the cleaning chamber 46.

[0103] The dust removal projection 66 is preferably provided across the entire width of the partition wall 65. The dust removal projection 66 only needs to be able to bend the brush bristles 59 of the rotating cleaning body 28. Therefore, the shape of the dust removal projection 66 may be comb-shaped as shown in Figures 5 and 6, or it may be a plate shape with a uniform protrusion length across the entire width. Since the rolling resistance of the rotating cleaning body 28 increases when the dust removal projection 66 makes contact, the shape of the dust removal projection 66 is appropriately set according to the output of the electric motor 29.

[0104] If the contact surface of the suction port body 16 is taken as the reference plane, the front projection 66F is substantially parallel to the reference plane. The rear projection 66R is inclined and protrudes in a direction away from the reference plane.

[0105] Generally, the user moves the suction port 16 forward to bring it into the uncleaned surface f. At this time, thread-like dust on the surface f moves from the front to the rear of the suction port 16. By making the front projection 66F substantially parallel to the reference plane, while tilting the rear projection 66R away from the reference plane, it becomes difficult for thread-like dust to enter both the front cleaning chamber 46F and the rear cleaning chamber 46R.

[0106] Furthermore, the rear partition wall 65R has holes 73 connecting the suction chamber 45 and the rear cleaning chamber 46R. The holes 73 are located within the area sandwiched between the left and right inclined surfaces 71. There may be multiple holes 73. The holes 73 discharge dust that has entered the rear cleaning chamber 46R to the suction chamber 45 so that it does not remain in the rear cleaning chamber 46R.

[0107] Furthermore, dust that enters the front cleaning chamber 46F is discharged forward of the suction port 16 as the front cleaning chamber 28F rotates. In other words, dust that enters the front cleaning chamber 46F has a greater chance of being sucked into the suction port 27 as the suction port 16 moves forward than dust that enters the rear cleaning chamber 46R. For this reason, the front partition wall 65F does not need to have holes 73 like the rear partition wall 65R.

[0108] Furthermore, if dust enters the cleaning chamber 46, the user can visually inspect the dust that has entered the cleaning chamber 46 through the permeable wall 47. In other words, the user can visually inspect whether or not dust has entered the front cleaning chamber 46F through the first permeable wall 47A, and whether or not dust has entered the rear cleaning chamber 46R through the second permeable wall 47B.

[0109] A projection 75 is provided on a part of the opening edge of the rear cleaning chamber 46R, where it faces the rear projection 66R, and has a vertical cross-sectional shape that is acute toward the rear cleaning body 28R. The projection 75 is provided on the rear side of the opening edge of the rear cleaning chamber 46R. When the suction port body 16 is used on a soft surface to be cleaned f, such as a carpet, the suction port body 31 sinks into the surface to be cleaned f. In such cases, the projection 75 scrapes up the surface to be cleaned f like a bulldozer blade, scraping out dust and dirt that has gotten into the carpet.

[0110] Preferably, the protrusion 75 extends across the entire width of the rear cleaning chamber 46R. Also, when the suction port body 16 is used on a hard surface to be cleaned, such as flooring, the protrusion 75 may extend downward from the bottom surface 31a of the suction port body 31, to the extent that it does not come into contact with the surface to be cleaned f.

[0111] The suction port body 16 may also include three or more rotating cleaning bodies 28, including a front cleaning body 28F and a rear cleaning body 28R that sandwich the suction port 27 between them. In other words, the suction port body 16 may include three or more cleaning body chambers 46, which are partitioned outside the suction chamber 45 and include a front cleaning body chamber 46F and a rear cleaning body chamber 46R that sandwich the suction port 27 between them, and three or more rotating cleaning bodies 28, which include a front cleaning body 28F and a rear cleaning body 28R and are arranged in each cleaning body chamber 46. In this case, it is preferable that the number of cleaning body chambers 46 and rotating cleaning bodies 28 are the same. The number of electric motors 29, electric motor chambers 51, power transmission mechanisms 41 and machine chambers 52 may be the same as the number of cleaning body chambers 46 and rotating cleaning bodies 28, or they may be fewer than the number of cleaning body chambers 46 and rotating cleaning bodies 28, as long as they can rotate and drive multiple rotating cleaning bodies 28 in the same direction. For example, the driving force of one electric motor 29 may be distributed by the power transmission mechanism 41 to simultaneously rotate multiple rotating cleaning bodies 28 in the same direction. The number of electric motors 29, electric motor rooms 51, power transmission mechanisms 41, and machine rooms 52 may be greater than the number of cleaning body rooms 46 and rotating cleaning bodies 28. For example, multiple electric motors 29 may work together to drive one rotating cleaning body 28.

[0112] Furthermore, the suction port body 16 may be equipped with three or more permeable walls 47, including a first permeable wall 47A that visually covers the front cleaning body 28F, and a second permeable wall 47B that visually covers the rear cleaning body 28R. In this case, each permeable wall 47 is provided in each cleaning body chamber 46. The permeable member 56 may be all or part of the three or more permeable walls 47.

[0113] Figure 9 is a partial cross-sectional view of an inlet body according to an embodiment of the present invention.

[0114] As shown in Figures 5, 6, and 9, the suction port body 16 according to this embodiment is equipped with a resistance reduction mechanism 81 that protrudes from the bottom surface 31a of the suction port body 31 and moves away from the surface to be cleaned f when the multiple rotating cleaning bodies 28 move in a direction parallel to the rotation centerline, that is, in the left-right direction of the suction port body 16, thereby reducing the rolling resistance of the multiple rotating cleaning bodies 28.

[0115] The resistance reduction mechanism 81 includes a guide portion 82 that extends in the left-right direction from the suction port body 31 and is curved upward in a convex shape, a roller 83 that is movable along the guide portion 82, and an induction magnetic force portion 85 that positions the roller 83 in the center of the guide portion 82.

[0116] The guide section 82 is curved in an upward-convex arch shape.

[0117] When the roller 83 is located in the center of the guide section 82, it is preferable that it is separated from the surface to be cleaned f. When the suction port body 16 begins to move in either the left or right direction, the roller 83 makes contact with the surface to be cleaned f due to inertia. As the movement of the suction port body 16 continues, the frictional force between the roller 83 and the surface to be cleaned f overcomes the magnetic force of the inductive magnetic section 85 that tries to position the roller 83 in the center of the guide section, and the roller 83 protrudes from the bottom surface 31a of the suction port body 31. The amount of protrusion of the roller 83 is determined by the height difference between the center of the guide section 82 and each of its ends. When the roller 83 moves to each of the ends of the guide section 82 and protrudes from the bottom surface 31a of the suction port body 31, the roller 83 makes contact with the surface to be cleaned f, increasing the distance between the suction port body 31 and the surface to be cleaned f. As a result, the amount of contact between the rotating cleaning body 28 and the surface to be cleaned f decreases, reducing rolling resistance and increasing the agility of the suction port body 16 in the left-right direction.

[0118] Furthermore, the rotating part 83 may be a sled that moves away from the surface to be cleaned f and is also movable on the surface to be cleaned f.

[0119] The induction magnetic field unit 85 includes a fixed magnet 87 installed at the end of the guide unit 82 and a movable magnet 88 installed at the base of the roller 83. The polarity of the fixed magnet 87 and the polarity of the movable magnet 88 are set to repel each other. Due to this repulsion between the fixed magnet 87 and the movable magnet 88, the roller 83 is guided to the center of the guide unit 82, i.e., the neutral position. Therefore, if the roller 83 is not installed on the surface to be cleaned f, it will move to the neutral position by the induction magnetic field unit 85.

[0120] Next, other examples of the resistance reduction mechanism 81 of the suction port body 16 according to this embodiment will be described. In each example of the resistance reduction mechanism 81A, the same reference numerals are used for components that are the same as those in the resistance reduction mechanism 81, and redundant explanations are omitted.

[0121] Figure 10 is a partial cross-sectional view of another example of a suction port body according to an embodiment of the present invention.

[0122] As shown in Figure 10, the suction port body 16 according to this embodiment is equipped with a resistance reduction mechanism 81A that protrudes from the bottom surface 31a of the suction port body 31 and moves away from the surface to be cleaned f when the multiple rotating cleaning bodies 28 move in a direction parallel to the rotation centerline, that is, in the left-right direction of the suction port body 16, thereby reducing the rolling resistance of the multiple rotating cleaning bodies 28.

[0123] The resistance reduction mechanism 81A includes a guide portion 82A that extends from the left and right sides of the suction port body 31 and is curved upward in a convex shape, a roller 83 that is movable along the guide portion 82A, and an induction magnetic force portion 85A that positions the roller 83 in the center of the guide portion 82A.

[0124] The guide section 82A has a central arch-shaped section that is far from the bottom surface 31a of the suction port body 31 and gently convex upward, and a pair of parallel sections on the left and right that are close to the bottom surface 31a of the suction port body 31.

[0125] The induction magnetic field unit 85A has fixed magnets 87A installed at the left end of the left parallel section, both ends of the central section, and the right end of the right parallel section in Figure 9B, and a movable magnet 88 installed at the base of the roller 83. The polarity of the fixed magnet 87A and the polarity of the movable magnet 88 are set to repel each other. Due to this repulsion between the fixed magnet 87A and the movable magnet 88, the roller 83 is guided to the central part of the guide section 82A, i.e., the neutral position. Therefore, if the roller 83 is not installed on the surface to be cleaned f, it will move to the neutral position by the induction magnetic field unit 85A.

[0126] The suction port body 16 is movable in the front-to-back direction along the short side of the suction port main body 31, and is also movable left-to-right along the long side of the suction port main body 31 by the resistance reduction mechanism 81 and resistance reduction mechanism 81A. Travel along the short side of the suction port main body 31 is defined as movement in the front-to-back direction (along the solid arrow X in Figure 2), and travel along the long side of the suction port main body 31 is defined as movement in the left-to-right direction (along the solid arrow Y in Figure 2). Since the suction port body 16 is connected to the extension pipe 15 via a connecting pipe 32 which is a universal joint, it is also possible to travel with the short side of the suction port main body 31 facing left-to-right and the long side of the suction port main body 31 facing front-to-back from the user's perspective. In this case, the forward and backward movement of the suction port body 31 is equivalent to the left-right movement as viewed from the user, and the left-right movement of the suction port body 31 is equivalent to the forward and backward movement as viewed from the user. For the sake of explanation, the direction of movement of the suction port body 16 will be described using the coordinate system of the suction port body 16 (solid arrows X, Y, Z in Figure 2).

[0127] Figure 11 is a control block diagram of the suction port body according to an embodiment of the present invention.

[0128] As shown in Figure 11, the suction port body 16 according to this embodiment drives multiple electric motors 29 with power supplied from a secondary battery 13 attached to the vacuum cleaner body 12. The suction port body 16 comprises multiple rotating cleaning bodies 28, multiple electric motors 29 provided for each rotating cleaning body 28 to individually generate the driving force to rotate the rotating cleaning body 28, and a suction port body control unit 42 that controls the operation of the multiple electric motors 29.

[0129] The suction port control unit 42 is electrically connected to the secondary battery 13 by two wires 91 that reach the vacuum cleaner body 12 through the extension pipe 15. One of the two wires 91 is the ground wire 92, and the other of the two wires 91 is the ungrounded wire 93.

[0130] The intake port control unit 42 includes a control power generation circuit 95 that steps down the power supplied from the secondary battery 13 to output control power, a reference voltage generation circuit 96 that outputs a reference voltage, a plurality of drive circuits 97 provided for each motor 29, a current detection circuit 98 that individually detects the current flowing through each motor 29, and a drive force difference control circuit 99 that controls the current flowing through the plurality of motors 29 collectively based on the detection results of the current detection circuit 98. Each circuit is individually grounded.

[0131] The reference voltage generation circuit 96 generates a reference voltage for pulse width modulation (PWM) control using power supplied from the control power generation circuit 95 and outputs it to the drive force difference control circuit 99. The reference voltage is a triangular wave. The reference voltage generation circuit 96 outputs a triangular wave using an operational amplifier.

[0132] Each drive circuit 97 includes a switching element that switches the power input to the corresponding motor 29. Each drive circuit 97 individually opens and closes the corresponding switching element using pulse width modulation control.

[0133] Each switching element opens and closes the ungrounded wire 93 that supplies drive power from the secondary battery 13 to the corresponding motor 29. Each switching element is a bidirectional thyristor (Triode AC Switch, TRIAC), a reverse-blocking three-terminal thyristor (Silicon Controlled Rectifier, SCR), or a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). Each switching element has a gate connected to the corresponding drive force difference control circuit 99. The switching element changes the input (drive current) of the motor 29 in response to changes in gate current or gate voltage.

[0134] The current detection circuit 98 outputs a voltage value correlated with the detection result of the current flowing through each motor 29 to the drive force difference control circuit 99. The current detection circuit 98 includes a shunt resistor that converts the current flowing through each motor 29 into a voltage, and an amplification circuit that amplifies the voltage converted by the shunt resistor and outputs it to the corresponding drive force difference control circuit 99. The amplification circuit is a so-called differential amplifier circuit, comprising one operational amplifier and four resistors. The current detection circuit 98 may also consist of multiple separate, independent circuits for each motor 29.

[0135] The driving force difference control circuit 99 compares the voltage value output by the current detection circuit 98 with the reference voltage output by the reference voltage generation circuit 96 and switches the corresponding switching element of the driving circuit 97.

[0136] Generally, when a microcomputer or control circuit for controlling the operation of multiple electric motors 29 is installed in the vacuum cleaner body 12, the currents flowing through the multiple electric motors 29 can be detected and combined at the suction port 16 side, and the result of detecting this combined current can be input to the microcomputer or control circuit on the vacuum cleaner body 12 to control the operation of the multiple electric motors 29. This type of control is hereinafter referred to as the "combined current control type".

[0137] Furthermore, generally, when a microcomputer or control circuit for controlling the operation of multiple electric motors 29 is installed in the vacuum cleaner body 12, the current flowing through the multiple electric motors 29 can be individually detected at the suction port 16 side, and these individually detected currents can be individually input to the microcomputer or control circuit of the vacuum cleaner body 12 without combining them, thereby controlling the operation of the multiple electric motors 29. This type of control is hereinafter referred to as the "individual control type".

[0138] Furthermore, the combined current control type only needs to include at least two wires, including a power supply line that supplies power from the vacuum cleaner body 12 to the suction port 16, and a signal line that transmits the detection result of the combined current from the suction port 16 to the vacuum cleaner body 12, in order to achieve operational control of multiple electric motors 29.

[0139] On the other hand, the individual control type requires at least three wires, including a power supply line that supplies power from the vacuum cleaner body 12 to the suction port 16, and multiple signal lines that transmit the detection results of the current flowing through each of the electric motors 29 from the suction port 16 to the vacuum cleaner body 12, in order to control the operation of multiple electric motors 29.

[0140] The combined current control type controls the inputs of multiple motors 29 collectively based on the combined current of multiple motors 29. In other words, in the combined current control type, the microcomputer or control circuit of the vacuum cleaner body 12 cannot individually grasp the load state of each motor 29. Therefore, there is a risk that the input of each motor 29 may become excessive or insufficient. If the input is excessive, the risk of a layer short circuit occurring in the motor 29 increases, while if the input is insufficient, the rotational speed of the rotating cleaning body 28 may decrease, and it may not be able to perform its dust removal function.

[0141] Furthermore, in the individually controlled type, while the microcomputer or control circuit of the vacuum cleaner body 12 can individually grasp the load state of each electric motor 29, it requires at least three wires between the vacuum cleaner body 12, including the extension pipe 15, and the suction port 16. If three or more wires are wired between the vacuum cleaner body 12 and the suction port 16, it leads to an enlargement of the tunnel structure through which the wires pass, and a corresponding increase in the weight of the electric vacuum cleaner 1. In other words, the individually controlled type hinders miniaturization and weight reduction of the electric vacuum cleaner 1.

[0142] Therefore, the suction port body 16 according to this embodiment includes a current detection circuit 98 provided for each motor 29, which individually detects the current flowing through each of the multiple motors 29, and a driving force difference control circuit 99 which individually limits the current flowing through each of the multiple motors 29 based on the detection results of the current detection circuit 98. If at least one of the multiple motors 29 becomes overloaded, the current detection circuit 98 detects the motor 29 in the overloaded state, and the driving force difference control circuit 99 switches the switching element of the drive circuit 97 corresponding to the motor 29 in the overloaded state to limit the current flowing through the motor 29 in the overloaded state. In other words, the suction port body control unit 42 detects the current value flowing through each motor 29 with the current detection circuit 98, and if this current value becomes excessive, the driving force difference control circuit 99 limits the current flowing through the motor 29 in the overloaded state. By doing so, the suction port body control unit 42 prevents a layer short from occurring in the motor 29 in the overloaded state, while allowing the operation of the other motors 29 that are not overloaded to continue.

[0143] Furthermore, the drive force difference control circuit 99 operates at least one electric motor 29 so that the leading rotating cleaning body 28 in the direction of travel rotates in the forward direction to assist its movement, and operates at least one other electric motor 29 so that at least one rotating cleaning body 28 following the leading rotating cleaning body 28 rotates in the reverse direction.

[0144] In this embodiment, when the suction port 16 is moving forward, the drive force difference control circuit 99 controls the front motor 29F to drive so that the front cleaning body 28F rotates in the forward direction, and controls the rear motor 29R to drive so that the rear cleaning body 28R rotates in the reverse direction. Also, when the suction port 16 is moving backward, the drive force difference control circuit 99 controls the rear motor 29R to drive so that the rear cleaning body 28R rotates in the forward direction, and controls the front motor 29F to drive so that the front cleaning body 28F rotates in the reverse direction.

[0145] Furthermore, the drive force difference control circuit 99 determines whether the suction port body 16 is moving forward or backward based on the detection result of the current detection circuit 98. In other words, the drive force difference control circuit 99 determines whether the multiple rotating cleaning bodies 28 are moving in a direction that intersects their rotational centerlines based on the detection result of the current detection circuit 98.

[0146] The suction port control unit 42 may be located in the vacuum cleaner body 12. In other words, the control power generation circuit 95, reference voltage generation circuit 96, drive circuit 97, current detection circuit 98, and drive force difference control circuit 99 of the suction port control unit 42 may be located in the vacuum cleaner body 12. Alternatively, the control power generation circuit 95, reference voltage generation circuit 96, drive circuit 97, current detection circuit 98, and drive force difference control circuit 99 may be distributed between the vacuum cleaner body 12 and the suction port 16.

[0147] Figure 12 is a graph showing an example of the current flowing through multiple motors in a suction port body according to an embodiment of the present invention.

[0148] Figure 12 shows the front drive current value IF flowing through the front motor 29F, the rear drive current value IR flowing through the rear motor 29R, and the time change of acceleration A in the front-rear direction of the suction port 16.

[0149] Incidentally, the suction port body 16 travels or slides on the surface to be cleaned f by a force acting via an extension pipe 15 that extends diagonally upward and backward (diagonally downward and forward from the user's perspective). The extension pipe 15 is connected to the suction port body 16 via a connecting pipe 32, which is a universal joint. When the suction port body 16 moves forward, a force acts from the extension pipe 15 to the suction port body 16 that pushes it forward and presses it against the surface to be cleaned f. When the suction port body 16 moves backward, a force acts from the extension pipe 15 to the suction port body 16 that pulls it backward and separates it from the surface to be cleaned f. In other words, the suction port body 16 is equipped with a connecting pipe 32, which acts as a joint that receives a force that advances the multiple rotating cleaning bodies 28 while loading them onto the surface to be cleaned f, and a force that retreats the multiple rotating cleaning bodies 28 while removing the load from the surface to be cleaned f.

[0150] Therefore, as shown in Figure 12, when the suction port 16 is moving forward, the rotational load acting on the motor 29 increases, and the forward drive current value IF and the backward drive current value IR increase. Conversely, when the suction port 16 is moving backward, the rotational load acting on the motor 29 decreases, and the forward drive current value IF and the backward drive current value IR decrease.

[0151] Based on this relationship, the driving force difference control circuit 99 determines whether the suction port body 16 is moving forward or backward.

[0152] Specifically, the drive force difference control circuit 99 detects changes in the direction of travel of the suction port 16 based on the difference in current values ​​flowing to at least two electric motors 29 that independently drive at least two rotating cleaning bodies 28 with different rotation directions, and determines which direction the multiple rotating cleaning bodies 28 are moving in as they intersect the rotation centerline. In other words, the drive force difference control circuit 99 detects changes in the direction of travel of the suction port 16 based on the difference in the front drive current value IF and the rear drive current value IR flowing to the front electric motor 29F and the rear electric motor 29R that independently drive the front cleaning body 28F and the rear cleaning body 28R, respectively, and determines which direction the multiple rotating cleaning bodies 28 are moving in as they intersect the rotation centerline.

[0153] Furthermore, the drive force difference control circuit 99 may detect a change in the direction of travel of the suction port 16 based on the difference in the change in the current values ​​flowing to at least two electric motors 29 that independently drive at least two rotating cleaning bodies 28 with different rotation directions, and determine which direction the multiple rotating cleaning bodies 28 are moving in as they intersect the rotation centerline. In other words, the drive force difference control circuit 99 may detect a change in the direction of travel of the suction port 16 based on the difference in the change in the front drive current value IF and the rear drive current value IR flowing to the front electric motor 29F and the rear electric motor 29R that independently drive the front cleaning body 28F and the rear cleaning body 28R, respectively, and determine which direction the multiple rotating cleaning bodies 28 are moving in as they intersect the rotation centerline. In this case, the drive force difference control circuit 99 detects a change in the direction of travel of the suction port 16 based on at least one of the temporal change in the pre-drive current value IF (slope in Figure 12) and the temporal change in the post-drive current value IR (slope in Figure 12), or the difference between them.

[0154] Furthermore, the drive force difference control circuit 99 may also detect a change in the direction of travel based on the current value flowing to the electric motor 29 that rotates the leading forward-rotating cleaning body 28, or a change in the current value flowing to the electric motor 29 that rotates the leading forward-rotating cleaning body 28. The rolling resistance acting on the front cleaning body 28F immediately after the suction port 16 changes direction from reverse to forward is clearly greater than the rolling resistance acting on the rear cleaning body 28R immediately after the suction port 16 changes direction from forward to reverse. Immediately after the suction port 16 changes direction from reverse to forward, the front cleaning body 28F rotates while loading the surface to be cleaned f. In other words, immediately after the rotation direction of the front cleaning body 28F changes from reverse rotation to forward rotation, the rolling resistance of the front cleaning body 28F increases sharply. On the other hand, immediately after the suction port 16 changes direction of travel from forward to backward, the rear cleaning body 28R rotates while releasing its weight from the surface to be cleaned f. In other words, immediately after the rotation direction of the rear cleaning body 28R changes from backward reverse rotation to forward forward rotation, the rolling resistance of the rear cleaning body 28R decreases sharply. Therefore, by alternately monitoring the forward drive current value IF flowing through the front motor 29F and the rear drive current value IR flowing through the rear motor 29R, the drive force difference control circuit 99 can detect a change in the current value flowing through the motor 29 that rotates the leading forward cleaning body 28, and thus detect a change in the direction of travel of the suction port 16. This detection of a change in the direction of travel of the suction port 16 by alternately monitoring the forward drive current value IF and the rear drive current value IR can also be achieved by detecting a change in the current value flowing through the motor 29 that rotates the leading backward reverse cleaning body 28.

[0155] Furthermore, the drive force difference control circuit 99 may also detect a change in the direction of travel and determine which direction the multiple rotating cleaning bodies 28 are moving in, intersecting the rotation centerline, based on the length of the duration of the peak current in which the front drive current value IF of the front motor 29F exceeds a predetermined judgment current Id. As shown in Figure 12, the duration of the peak current in which the front drive current value IF exceeds the judgment current Id is shorter than the duration of the peak current in which the rear drive current value IR exceeds the judgment current Id. Here, we focus on the current value flowing to the front motor 29F when the direction of travel of the suction port 16 changes from reverse to forward. When the direction of travel of the suction port 16 changes from reverse to forward, the front motor 29F is strongly pressed against the surface to be cleaned f and begins to rotate in the forward direction. At this time, the front drive current value IF flowing to the front motor 29F rises instantaneously. If the suction port 16 continues to move forward, the rotational load on the front motor 29F decreases, and the forward drive current value IF flowing to the front motor 29F drops sharply compared to the rear drive current value IR flowing to the rear motor 29R, which rotates in the reverse direction. By detecting such changes in current values, the drive force difference control circuit 99 can detect the direction of travel of the suction port 16.

[0156] Furthermore, while the suction port 16 is moving forward, the rotational load of the forward-rotating front cleaning body 28F decreases. Therefore, as shown in Figure 12, the front drive current value IF tends to increase temporarily and then gradually decrease. On the other hand, while the suction port 16 is moving forward, the rotational load of the reverse-rotating rear cleaning body 28R is always maintained at a high level. Therefore, as shown in Figure 12, the rear drive current value IR always maintains a high value while the suction port 16 is moving forward. Thus, by capturing the situation where the rear drive current value IR is high and a high load is maintained on the rear motor 29R, and the front drive current value IF temporarily increases and then decreases, the drive force difference control circuit 99 can detect the direction of travel of the suction port 16.

[0157] Furthermore, when the auxiliary force acting on the surface to be cleaned f from the leading forward-rotating cleaning body 28 and the resistance force acting on the surface to be cleaned f from the trailing, counter-rotating cleaning body 28 are balanced, these propulsive forces cancel each other out and do not contribute to either the forward or backward movement of the suction port 16. Also, if the resistance force is greater than the auxiliary force, the resultant force of the propulsive forces acts in the opposite direction to the direction of movement of the suction port 16, causing the user to feel resistance.

[0158] Therefore, the driving force difference control circuit 99 of the suction port 16 according to this embodiment operates multiple electric motors 29 such that the auxiliary force generated by the rotating cleaning body 28 that rotates in the forward direction ahead in the direction of travel of the suction port 16 is greater than the resistance force generated by the rotating cleaning body 28 that rotates in the reverse direction behind in the direction of travel.

[0159] Furthermore, the auxiliary force and resistance force are forces generated as multiple rotating cleaning bodies 28 rotate while in contact with a homogeneous surface to be cleaned f, specifically a surface f with substantially the same coefficient of friction, regardless of the differences in the composition of each rotating cleaning body 28, such as the density of the brush bristles or the presence or absence of a silicone blade. Therefore, under conditions where the front cleaning body 28F and the rear cleaning body 28R are in contact with a homogeneous surface to be cleaned f and no external forces are acting, the auxiliary force is always greater than the resistance force.

[0160] Furthermore, the amplitudes of the pre-drive current value IF and post-drive current value IR shown in Figure 12 change according to the magnitude of the rotational load of the corresponding motor 29. The rolling resistance on a surface to be cleaned, such as a carpet, is greater than the rolling resistance on a smooth surface to be cleaned, such as a wooden floor or hardwood floor. In other words, the rotational load of the motor 29 that rotates the rotating cleaning body 28 on a surface to be cleaned, such as a carpet, is greater than the rotational load of the motor 29 that rotates the rotating cleaning body 28 on a smooth surface to be cleaned, such as a wooden floor or hardwood floor. Consequently, the current value flowing through the motor 29 that rotates the rotating cleaning body 28 on a surface to be cleaned, such as a carpet, is greater than the current value flowing through the motor 29 that rotates the rotating cleaning body 28 on a smooth surface to be cleaned, such as a wooden floor or hardwood floor. Therefore, the driving force difference control circuit 99 can estimate the rolling resistance due to friction of the surface to be cleaned f in contact with the rotating cleaning body 28, which is rotationally driven by the motors 29, based on the current value flowing through at least one of the motors 29, the change in the current value, or the magnitude of the peak current where the current value exceeds a predetermined second determination current.

[0161] The drive force difference control circuit 99 then sends first drive power to multiple motors 29 if the estimated rolling resistance is greater than a predetermined rolling resistance, for example, when the rotating cleaning body 28 is rotating on a carpet. The drive force difference control circuit 99 also sends second drive power, which is smaller than the first drive power, to multiple motors 29 if the estimated rolling resistance is less than or equal to a predetermined rolling resistance, for example, when the rotating cleaning body 28 is rotating on a smooth surface to be cleaned f such as a wooden floor or hardwood floor. In other words, the drive force difference control circuit 99 estimates the magnitude of the rolling resistance of the surface to be cleaned f in contact with the rotating cleaning body 28 from the rotational load of the motors 29, and changes the magnitude of the operating output of the motors 29 in accordance with the estimated magnitude of the rolling resistance of the surface to be cleaned f. In this way, the suction port 16 can maximize its dust removal performance with efficient power consumption suitable for the properties of the surface to be cleaned f. Furthermore, even on a surface to be cleaned where the rolling resistance of the rotating cleaning body 28 changes depending on whether it is moving in the direction of the grain or against the grain, such as on a carpet, the suction port 16 can maximize its dust removal performance with efficient power consumption suitable for the properties of the surface f to be cleaned, regardless of whether it moves forward in the direction of the grain and backward in the direction of the grain, or backward in the direction of the grain and forward in the direction of the grain.

[0162] The suction port 16 obtains its self-propelled output from the difference between the assisting force and the resisting force. Therefore, the smaller the rotational torque of the motor 29 rotating in the reverse direction, the easier it is to increase the self-propelled output of the suction port 16. However, the motor 29 rotating in the reverse direction plays an important role in removing dust from the surface to be cleaned f. In other words, if the rotational torque of the motor 29 rotating in the reverse direction is small, the dust removal performance of the suction port 16 will decrease significantly. Therefore, there is a trade-off between the self-propelled output of the suction port 16 and the dust removal performance of the suction port 16. This problem can be solved by using a motor 29 with high rotational torque, but if the rotational torque of the motor 29 is simply made too large, there is a risk that it will not collect the dust but rather blow it away. Therefore, the suction port 16 according to this embodiment achieves both self-propelled output of the suction port 16, dust removal performance of the suction port 16, and prevention of dust scattering of the suction port 16 by appropriately setting the driving power (first driving power, second driving power) according to the properties of the surface f to be cleaned.

[0163] Therefore, the ratio of the first drive power (the drive power corresponding to the surface to be cleaned f with high rolling resistance, such as a carpet) to the second drive power (the drive power corresponding to the surface to be cleaned f with low rolling resistance, such as a wooden floor or hardwood flooring) is set to, for example, 13:7. In addition, the ratio of the auxiliary force (thrust force FF) to the resistance force (thrust force FR) in the first drive power is set to, for example, 10:3, and the ratio of the auxiliary force (thrust force FF) to the resistance force (thrust force FR) in the second drive power is set to, for example, 5:2. These drive force setting ratios of the electric motor 29 suitably balance the self-propelled output of the suction port 16, the dust removal performance of the suction port 16, and the prevention of dust scattering by the suction port 16.

[0164] Furthermore, unlike the determination current Id, the second determination current is preferably set to an appropriate value that allows for the determination of the properties of the surface f to be cleaned.

[0165] Furthermore, the driving force difference control circuit 99 may also estimate the time intervals in which the multiple rotating cleaning bodies 28 move in a direction intersecting the rotation centerline, based on the intervals in which peak currents occur, where the current value flowing through at least one of the multiple electric motors 29 exceeds a predetermined third determination current Id3.

[0166] As shown in Figure 12, in the section where the current values ​​flowing through the multiple electric motors 29, i.e., the forward drive current value IF and the backward drive current value IR, exceed the third determination current Id3, it can be seen that the suction port 16 is moving forward. Note that the third determination current Id3 may be the same as the determination current Id, and it is preferable to set it to an appropriate value that can distinguish the movement of multiple rotating cleaning bodies 28 on various cleaning surfaces f with different properties.

[0167] The drive force difference control circuit 99 sets the difference between the auxiliary force (thrust force FF) generated by the leading forward-rotating cleaning body 28 in the direction of travel of the suction port 16 and the resistance force (thrust force FR) generated by the trailing backward-rotating cleaning body 28 in the opposite direction of travel as the first difference if the estimated time interval for travel is shorter than a predetermined time interval. The drive force difference control circuit 99 also sets the difference between the auxiliary force and the resistance force as a second difference, which is larger than the first difference, if the estimated time interval is longer than a predetermined time interval. In this way, if the time interval between the forward and backward movement of the suction port 16, or the period between the forward and backward movement of the suction port 16, is short and it is estimated that the suction port 16 is moving at high speed, the difference between the auxiliary force and the resistance force is set to a smaller first difference, prioritizing the dust removal force by the trailing backward-rotating cleaning body 28. Furthermore, if the interval between the forward and backward movement of the suction port 16 is long and it is estimated that the suction port 16 is moving slowly, the difference between the assisting force and the resisting force is set to a larger second difference, and priority is given to assisting movement by the rotating cleaning body 28 which is rotating in the preceding forward direction.

[0168] Incidentally, if the interval between the forward and backward movement of the suction port 16, or the period between the forward and backward movement of the suction port 16, is short, and it is estimated that the suction port 16 is moving at high speed, it is estimated that the user of the vacuum cleaner 1 is in a hurry to complete the cleaning. In this case, it is in the user's best interest to increase the dust removal capacity, even if it increases the power consumption of the secondary battery 13 and shortens the operating time.

[0169] Therefore, the magnitude of the resistance force that generates the first difference is set to be greater than the resistance force that generates the second difference. The driving force difference control circuit 99 sets the difference between the auxiliary force and the resistance force as the first difference when the estimated time interval for travel is shorter than a predetermined time interval, and increases the magnitude of the resistance force to be greater than the magnitude of the resistance force when the estimated time interval is greater than or equal to the predetermined time interval. In other words, when the estimated time interval for travel is greater than or equal to the predetermined time interval, the difference between the auxiliary force and the resistance force is set as the second difference, and the magnitude of the resistance force is smaller than the magnitude of the resistance force when the estimated time interval is shorter than the predetermined time interval. In this way, the suction port body 16 can achieve an appropriate balance between self-propelled output that suits the user's characteristics and intentions and dust scraping ability. In this case, if the second difference is greater than the first difference, the driving force difference control circuit 99 may maintain the propulsion force, or it may change the propulsion force along with the resistance force.

[0170] Furthermore, users with weak arm strength may find it difficult to move the suction nozzle 16 at high speed. In other words, if the interval between the forward and backward movement of the suction nozzle 16, or the period between the forward and backward movement of the suction nozzle 16, is long, and it is estimated that the suction nozzle 16 is moving at a low speed, it can be assumed that the user of the vacuum cleaner 1 is a woman or child with weak arm strength. In this case, it is in the user's best interest to reduce the power consumption of the secondary battery 13 and extend the operating time, even at the expense of dust removal capacity.

[0171] Therefore, the magnitude of the thrust force that generates the second difference is set to be smaller than the thrust force that generates the first difference. The drive force difference control circuit 99 sets the difference between the auxiliary force and the resistance force to the second difference if the estimated time interval for travel is greater than or equal to a predetermined time interval, and reduces the magnitude of the thrust force to be greater than the magnitude of the thrust force when the estimated time interval is shorter than the predetermined time interval. In other words, if the estimated time interval for travel is shorter than the predetermined time interval, the difference between the auxiliary force and the resistance force is set to the first difference, and the magnitude of the thrust force is greater than the magnitude of the thrust force when the estimated time interval is greater than or equal to the predetermined time interval. In this way, the intake port 16 can achieve an appropriate balance between self-propelled output that suits the user's characteristics and intentions and dust scraping ability. In this case, if the second difference is greater than the first difference, the drive force difference control circuit 99 may maintain the resistance force, or it may change the resistance force along with the thrust force. It is preferable to maintain resistance or set a lower limit for resistance to avoid a significant decrease in the dust removal capacity of the rotating cleaning body 28 when it rotates in the reverse direction.

[0172] These controls, which increase or decrease at least one of the thrust and resistance forces in accordance with the speed of travel of the suction port 16, are not limited to two stages of magnitude relationships (high / low travel speed, magnitude of thrust, and magnitude of resistance), but may control three or more magnitude relationships, or they may control linear magnitude relationships.

[0173] Furthermore, if the interval between the forward and backward movement of the suction port 16 is short, it can be inferred that the user has the arm strength to move the suction port 16 quickly or has a desire to finish cleaning quickly. Therefore, the dust removal power of the reversing rotating cleaning body 28 is prioritized by setting the difference between the assisting force and the resisting force to the smaller first difference.

[0174] Furthermore, if the interval between the forward and backward movement of the suction port 16 is long, it can be inferred that the user has low arm strength or is cleaning carefully. Therefore, the difference between the assisting force and the resisting force is set to a larger second difference to increase the self-propelled output of the suction port 16 and provide a lighter operating feel.

[0175] In other words, the suction port body 16 can achieve an appropriate balance between self-propelled output and dust removal capacity that suits the user's characteristics and preferences.

[0176] Furthermore, when the suction port 16 is retracting, the leading cleaning body 28R, which rotates in the forward direction, generates a greater thrust than the leading cleaning body 28F, which rotates in the reverse direction. In this situation, if the user tries to move the suction port 16 forward, they may experience an unpleasant sensation such as catching due to the thrust force that tries to move the suction port 16 in the retracting direction. Also, if the user tries to move the retracting suction port 16 forward, the force acting from the suction port 16 on the surface to be cleaned f changes from a state where it is unloading the surface to be cleaned f to a state where it is loading the surface to be cleaned f.

[0177] Therefore, the drive force difference control circuit 99 according to this embodiment may operate the front motor 29F immediately after determining that the direction of travel of the multiple rotating cleaning bodies 28 has switched from reverse to forward, so as to increase the difference between the auxiliary force and the resistance force. By doing so, when the direction of travel of the suction port body 16 switches from reverse to forward, the feeling of resistance caused by the thrust force that tries to move the suction port body 16 in the reverse direction is reduced, and the ease of operation when starting to move forward is improved.

[0178] As shown in Figure 12, the acceleration A acting on the suction port 16 reverses its tendency to increase or decrease when the suction port 16 changes direction of travel, from forward to backward, or from backward to forward. Therefore, as shown in Figure 11, the suction port 16 may be equipped with an acceleration sensor 101 that detects acceleration in a direction intersecting the rotation centerlines of the multiple rotating cleaning bodies 28. The driving force difference control circuit 99 starts determining the direction of travel based on the detection result of the current detection circuit 98 when the direction of acceleration detected by the acceleration sensor 101 reverses. In this way, the driving force difference control circuit 99 can more reliably determine whether the suction port 16 is moving forward or backward. By acquiring the detection result of the acceleration sensor 101 at predetermined time intervals and averaging the slope to calculate, the tendency of increase or decrease in acceleration in the forward and backward direction of the suction port 16 can be grasped more accurately.

[0179] As described above, the suction port 16 and vacuum cleaner 1 according to this embodiment operate multiple electric motors 29 such that the auxiliary force generated in the direction of travel by the rotating cleaning body 28 that rotates in the forward direction is greater than the resistance force generated in the opposite direction of travel by the rotating cleaning body 28 that rotates in the reverse direction behind. Therefore, the suction port 16 outputs a force biased toward the direction of travel. Conventional suction ports have had difficulty achieving both self-propelled output and dust removal capability for various surfaces to be cleaned with different properties, but the suction port 16 and vacuum cleaner 1 according to this embodiment can easily achieve both self-propelled output and dust removal capability suitable for various surfaces to be cleaned with different properties. These suitable self-propelled output and dust removal capabilities dramatically improve the comfort of operating the suction port 16. Furthermore, in conventional suction nozzles, the distance between the suction nozzle and the surface to be cleaned had to be set to a moderate level in order to accommodate various surfaces with different properties. However, in the suction nozzle 16 and vacuum cleaner 1 according to this embodiment, the suction nozzle body 31 can be brought close to the surface to be cleaned f so that the suction capacity is maximized for various surfaces with different properties. As a result, the dust removal capacity of the rotating cleaning body 28 can be maximized.

[0180] Furthermore, the suction port 16 and vacuum cleaner 1 according to this embodiment can detect changes in the direction of travel based on the difference in current values ​​flowing through at least two electric motors 29 that independently drive at least two rotating cleaning bodies 28 with different rotation directions, or the difference in the change in these current values. Therefore, the suction port 16 and vacuum cleaner 1 can easily and reliably determine the direction of travel of the suction port 16 without using any special devices or detectors.

[0181] Furthermore, the suction port 16 and vacuum cleaner 1 according to this embodiment may detect changes in the direction of travel based on the current value flowing through the electric motor 29 that rotates at least one rotating cleaning body that is rotating in the forward direction, or based on changes in this current value. Therefore, the suction port 16 and vacuum cleaner 1 can easily and reliably determine the direction of travel of the suction port 16 without using any special devices or detectors.

[0182] Furthermore, the suction port 16 and vacuum cleaner 1 according to this embodiment can detect changes in the direction of travel based on the length of the duration of the peak current, which exceeds a predetermined determination current Id, in the motor 29 that rotates the leading forward-rotating rotating cleaning body 28, and determine which direction the multiple rotating cleaning bodies 28 are moving in, intersecting the rotation centerline. In other words, the suction port 16 and vacuum cleaner 1 are equipped with a motor 29 that rotates the leading forward-rotating rotating cleaning body 28 and a motor 29 that rotates the trailing backward-rotating rotating cleaning body 28, and by individually detecting the current values ​​flowing through these motors 29, the direction of travel of the suction port 16 can be easily and reliably determined without using any special devices or detectors.

[0183] Furthermore, in this embodiment, the suction port 16 and vacuum cleaner 1 may initiate a determination of the direction of travel based on the detection result of the current detection circuit 98 when the direction of acceleration of the suction port 16 in the forward and backward direction, as detected by the acceleration sensor 101, reverses. Therefore, the suction port 16 and vacuum cleaner 1 can detect the change in direction of travel with higher accuracy and precision than if the change in direction of travel were detected solely by the acceleration sensor 101. When the change in direction of travel is detected solely by the acceleration sensor 101, if the suction port 16 stops or moves at a substantially constant speed, and the detected acceleration becomes extremely small, there is a risk of misdetection or failure to detect the change in direction of travel.

[0184] Furthermore, the suction port 16 and vacuum cleaner 1 according to this embodiment estimate the rolling resistance due to friction of the surface to be cleaned f in contact with the rotating cleaning body 28, which is rotationally driven by the motors 29, based on the current value, the change in the current value, or the magnitude of the peak current in which the current value exceeds a predetermined second determination current, in contact with at least one of the motors 29 of the plurality of motors 29. If the estimated rolling resistance is greater than a predetermined rolling resistance, a first drive power is sent to the plurality of motors 29, and if the estimated rolling resistance is less than or equal to the predetermined rolling resistance, a second drive power smaller than the first drive power is sent to the plurality of motors 29. As a result, the suction port 16 and vacuum cleaner 1 can maximize their dust removal performance with efficient power consumption suitable for the properties of the surface to be cleaned f. Furthermore, even on a surface to be cleaned where the rolling resistance of the rotating cleaning body 28 changes depending on whether it is moving in the direction of the grain or against the grain, such as on a carpet, the suction port 16 and the vacuum cleaner 1 can maximize their dust removal performance with efficient power consumption suitable for the properties of the surface f to be cleaned, regardless of whether they are moving forward in the direction of the grain and backward in the direction of the grain, or backward in the direction of the grain and forward in the direction of the grain.

[0185] Furthermore, the suction port 16 and vacuum cleaner 1 according to this embodiment estimate the time interval at which the multiple rotating cleaning bodies 28 move in a direction intersecting the rotation centerline, based on the occurrence interval of a peak current where the current value flowing through at least one of the multiple electric motors 29 exceeds a predetermined third determination current Id3. If the estimated time interval is shorter than a predetermined time interval, the difference between the assisting force and the resisting force is set to the first difference. If the estimated time interval is equal to or greater than the predetermined time interval, the difference between the assisting force and the resisting force is set to the second difference, which is greater than the first difference. Therefore, it is possible to achieve an appropriate balance between self-propelled output that suits the user's characteristics and intentions and dust removal capacity.

[0186] Furthermore, the suction port body 16 and the vacuum cleaner 1 according to this embodiment may also be equipped with a resistance reduction mechanism 81,**A that protrudes from the bottom surface 31a of the suction port body 31 and moves the suction port body 31 away from the surface to be cleaned f when the multiple rotating cleaning bodies 28 move in a direction parallel to the rotation centerline, thereby reducing the rolling resistance of the multiple rotating cleaning bodies 28. Therefore, the suction port body 16 and the vacuum cleaner 1 can reduce the amount of contact between the rotating cleaning bodies 28 and the surface to be cleaned f not only when the suction port body 16 is moved in the front-to-back direction, but also when the suction port body 16 is moved in the left-to-right direction, thereby improving the ease of operation in all four directions.

[0187] Furthermore, in this embodiment, the suction port 16 and the vacuum cleaner 1 operate multiple electric motors 29 immediately after determining that the direction of travel of the multiple rotating cleaning bodies 28 has switched from backward to forward, so as to increase the difference between the assisting force of the front cleaning body 28F and the resisting force of the rear cleaning body 28R. Therefore, when the direction of travel of the suction port 16 switches from backward to forward, the suction port 16 and the vacuum cleaner 1 reduce the feeling of resistance caused by the propulsive force that tries to move the suction port 16 backward, and improve the ease of operation when starting to move forward.

[0188] Therefore, according to the suction port 16 and vacuum cleaner 1 of this embodiment, a rotating cleaning body 28 that rotates in the forward direction and a rotating cleaning body 28 that rotates in the reverse direction are provided, and both smooth movement and dust collection performance can be achieved to accommodate various surfaces to be cleaned.

[0189] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0190] 1...Electric vacuum cleaner, 11...Handle, 12...Vacuum cleaner body, 13...Rechargeable battery, 15...Extension tube, 16...Suction port body, 17...Main body case, 17a...Front part, 17b...Rear part, 18...Electric blower, 19...Dust separation and collection unit, 21...Main body control unit, 23...Main body connection port, 26...Input unit, 26a...Start switch, 26b...Stop switch, 26c...Brush switch, 27...Suction port, 28...Rotating cleaning body, 28F...Front cleaning body, 28Fa...Top of front cleaning body, 28R...Rear cleaning body, 28Ra...Top of rear cleaning body, 28pr...Preceding rotation Rotating cleaning body, 28fo...rear rotating cleaning body, 29...electric motor, 29F...forward electric motor, 29R...rear electric motor, 29a...output shaft, 29pr...forward drive electric motor, 29fo...rear drive electric motor, 31...suction port body, 31a...bottom surface, 32...connecting pipe, 35...lower case, 36...upper case, 38...rotating connecting pipe, 39...oscillating connecting pipe, 41...power transmission mechanism, 41F...forward transmission mechanism, 41R...rear transmission mechanism, 42...suction port body control unit, 45...suction chamber, 46...cleaning body chamber, 46F...front cleaning body chamber, 46R...rear cleaning body chamber, 47...permeable wall 47A...First permeable wall, 47B...Second permeable wall, 47BL, 47BR...Divided permeable wall, 48...Air passage cover, 49...Air passage constrictor, 50...Rotation, 51...Motor room, 51F...Front motor room, 51R...Rear motor room, 52...Machine room, 52F...Front machine room, 52R...Rear machine room, 53...Control room, 55...Window section, 55F...Front cleaning body window, 55R...Rear cleaning body window, 55RL, 55RR...Divided window, 56...Permeable member, 57...Intermediate pipe, 59...Brush bristles, 61...Driver gear, 62...Driven gear, 63...Belt, 65...Bulkhead, 65F...Front bulkhead Wall, 65R...rear partition wall, 66...dust removal projection, 66F...front projection, 66R...rear projection, 68...curved surface, 71...inclined surface, 72...guide surface, 73...hole, 75...protrusion, 81, 81A...resistance reduction mechanism, 82, 82A...guide section, 83...rotating, 85, 85A...inductive magnetic force section, 87, 87A...fixed magnet, 88...movable magnet, 91...electric wire, 92...grounded electric wire, 93...ungrounded electric wire, 95...control power generation circuit, 96...reference voltage generation circuit, 97...drive circuit, 98...current detection circuit, 99...driving force difference control circuit, 101...accelerometer.

Claims

1. Multiple rotating cleaning bodies having parallel rotational centerlines, Multiple electric motors that generate rotational driving force for the multiple rotating cleaning bodies, A current detection circuit for individually detecting the current flowing through each of the aforementioned electric motors, The system comprises a control unit that controls the operation of the plurality of electric motors, The control unit, Based on the detection result of the current detection circuit, it is determined which direction the plurality of rotating cleaning bodies are moving in that intersects the rotation centerline. At least one of the electric motors is operated so that the rotating cleaning body, which is ahead in the direction of travel, rotates in a forward rotation direction that assists its movement. The other at least one electric motor is operated so that at least one of the rotating cleaning bodies follows the preceding rotating cleaning body and rotates in the opposite direction. The multiple electric motors are operated such that the auxiliary force generated in the direction of travel by the forward-rotating cleaning body is greater than the resistance force generated in the opposite direction of travel by the reverse-rotating cleaning body. Based on the interval at which peak currents occur in which the current flowing through at least one of the aforementioned multiple electric motors exceeds a predetermined determination current, the time interval at which the multiple rotating cleaning bodies move in a direction intersecting the rotation centerline is estimated. If the estimated time interval is shorter than a predetermined time interval, the difference between the auxiliary force and the resistive force is set as the first difference. If the estimated time interval is greater than or equal to a predetermined time interval, the suction port body sets the difference between the auxiliary force and the resistive force to a second difference that is greater than the first difference.

2. The suction port body according to claim 1, wherein the control unit detects a change in the direction of travel based on the current value flowing through the electric motor that rotates at least one of the rotating cleaning bodies that rotates in the forward direction, or a change in the current value flowing through the electric motor that rotates at least one of the rotating cleaning bodies that rotates in the forward direction, and determines in which direction the plurality of rotating cleaning bodies are moving in that intersect the rotation centerline.

3. The system includes an acceleration sensor that detects acceleration in a direction intersecting the rotational centerline of the plurality of rotating cleaning bodies, The suction port body according to claim 1 or 2, wherein the determination of the direction of travel based on the detection result of the current detection circuit is initiated when the direction of acceleration is reversed.

4. The control unit estimates the rolling resistance due to friction of the surface to be cleaned in contact with the rotating cleaning body, which is rotationally driven by the electric motor, based on the current value flowing through at least one of the plurality of electric motors, the change in the current value, or the magnitude of the peak current in which the current value exceeds a predetermined determination current. The suction port body according to any one of claims 1 to 3, wherein if the estimated rolling resistance is greater than a predetermined rolling resistance, a first drive power is sent to the plurality of motors, and if the estimated rolling resistance is less than or equal to the predetermined rolling resistance, a second drive power less than the first drive power is sent to the plurality of motors.

5. The suction port body according to any one of claims 1 to 4, wherein the magnitude of the resistance force that generates the first difference is greater than the resistance force that generates the second difference.

6. The suction port body according to any one of claims 1 to 5, wherein the magnitude of the resistance force that generates the second difference is smaller than the resistance force that generates the first difference.

7. A main body that rotatably supports the plurality of rotating cleaning bodies, The suction port body according to any one of claims 1 to 6, further comprising a resistance reduction mechanism that protrudes from the bottom surface of the main body to move the main body away from the surface to be cleaned and reduce the rolling resistance of the plurality of rotating cleaning bodies when the plurality of rotating cleaning bodies move in a direction parallel to the rotation center line.

8. The device includes a joint that receives a force to advance the plurality of rotating cleaning bodies while applying load to the surface to be cleaned, and a force to retract the plurality of rotating cleaning bodies while removing the load from the surface to be cleaned, The suction port according to any one of claims 1 to 7, wherein the control unit operates the multiple electric motors so as to increase the difference between the auxiliary force and the resistance force immediately after determining that the direction of travel of the multiple rotating cleaning bodies has switched from backward to forward.

9. The vacuum cleaner body and An electric blower housed in the vacuum cleaner body that generates negative pressure, A vacuum cleaner comprising a suction port body according to any one of claims 1 to 8, which is fluidly connected to the electric blower.

10. Multiple rotating cleaning bodies having parallel rotational centerlines, Multiple electric motors that generate rotational driving force for the multiple rotating cleaning bodies, A current detection circuit for individually detecting the current flowing through each of the aforementioned electric motors, The system comprises a control unit that controls the operation of the plurality of electric motors, The control unit, Based on the detection result of the current detection circuit, it is determined which direction the plurality of rotating cleaning bodies are moving in that intersects the rotation centerline. At least one of the electric motors is operated so that the rotating cleaning body, which is ahead in the direction of travel, rotates in a forward rotation direction that assists its movement. The other at least one electric motor is operated so that at least one of the rotating cleaning bodies follows the preceding rotating cleaning body and rotates in the opposite direction. The multiple electric motors are operated such that the auxiliary force generated in the direction of travel by the forward-rotating cleaning body is greater than the resistance force generated in the opposite direction of travel by the reverse-rotating cleaning body. Based on the interval at which peak currents occur in which the current flowing through at least one of the aforementioned multiple electric motors exceeds a predetermined determination current, the time interval at which the multiple rotating cleaning bodies move in a direction intersecting the rotation centerline is estimated. If the estimated time interval is shorter than a predetermined time interval, the difference between the auxiliary force and the resistive force is set as the first difference. If the estimated time interval is greater than or equal to a predetermined time interval, the vacuum cleaner sets the difference between the auxiliary force and the resistive force to a second difference that is greater than the first difference.

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