257 results about "Groove width" patented technology

The present invention provides a motorcycle tire capable of improving uneven wear resistance while maintaining wet performance. A motorcycle tire (1) has a tread portion (2). A tread portion (2) is provided with a plurality of first inclined grooves (3) that open from a crown region (Cr) toward a first tread edge (T1). The first inclined groove (3) includes a first portion (7) in which the groove width (W1) decreases from the crown region (Cr) toward the first tread edge (T1), and a second portion (8) in which the groove width (W1) increases toward the first tread edge (T1) to the first tread edge (T1).

The invention provides a double-groove structure design method for enhancing the sorting performance of a spiral chute, and relates to the technical field of spiral chute structural design. The double-groove structure design method comprises the steps that S1, the inner diameter and the outer diameter of a first groove and the outer diameter of a second groove are selected; s2, selecting a groove spiral line form as an equiangular spiral line, and selecting equiangular spiral line spiral angles of the first groove and the second groove; s3, selecting the maximum depth and the minimum depth of the groove; s4, an adjacent angle between the first groove and the second groove is selected, and the width of the grooves and the total number of the grooves of the spiral chute are selected; s5, the vertical distance between an outlet of the second groove and an inlet of the first groove is selected; and S6, performance checking is conducted on the designed double-groove structure used for enhancing the sorting performance of the spiral chute, if the performance meets the standard, design is ended, and if the performance does not meet the standard, the steps 1-6 are repeated. Rapid and efficient design of the groove structure can be achieved, and powerful technical support is provided for improving the performance of the spiral chute.

A trough width adjustment device for a comma scraper coater includes a trough body, a first and a second baffle plate, one end of the first and second baffle plates corresponding to the bottom roller is provided with a clearance notch, the first and second baffle plates are fixedly provided with a guide column extending in the horizontal direction, the trough wall of the trough body is provided with a guide hole, the first and second baffle plates are arranged in the trough body, and are matched with the gap of the bottom roller through the corresponding first clearance notch, the guide column on the baffle plate passes through the guide hole on the corresponding trough wall, so that the baffle plate is slidably matched in the trough bottom of the trough body, and also includes two rotating shafts, the rotating shafts are threadedly matched on the trough wall of the trough body, one end of the rotating shaft extends out of the trough body, a handle is fixedly installed, and a boss is provided at the other end, and idlingly matched in the corresponding baffle plate. The utility model has a simple structure and low modification cost, can accurately adjust the interval space between the two baffle plates, adapt to label tapes of different widths, and meet the actual needs of enterprises.

The application provides a numerical control machining method for an end face ring groove, and relates to the field of numerical control machining.The numerical control machining method for the end face ring groove comprises the following steps: obtaining the cross-sectional shape of the end face ring groove; determining the real-time groove width of the tool shaft when feeding according to the cross-sectional shape and the real-time groove depth of the tool shaft when feeding; determining the center track radius of the tool shaft according to the real-time groove width and the width of the blade; determining a track circle which is concentric with the center of the center circle and has a radius equal to the center track radius according to the center of the center circle of the end face ring groove; coinciding the symmetric center of the inner and outer edges of the blade with the center of the center circle, coinciding the shaft center of the tool shaft with the center of the center circle, and controlling the rotation of the tool shaft to cut out the ring groove.The technical scheme of the application greatly improves the utilization rate of the tool, reduces the production cost, and covers a wide range of machining of the end face ring groove.

Staple magazine, characterized in that the staple magazine is designed with a feed groove (113) and several staple groove groups (114), wherein the feed groove (113) extends along a first predetermined direction and is configured such that a cutting edge passes through the feed groove, and wherein each of the staple groove groups (114) comprises several staple grooves (1141) distributed along the first predetermined direction, and wherein the staple groove (1141) is configured for mounting a staple (4), and wherein the several staple groove groups (114) are spaced apart along the groove width direction of the feed groove (113), and wherein at least one staple groove group (114) is distributed on both sides of the feed groove (113) in the groove width direction, and wherein the number of staple groove groups (114) on both sides of the feed groove (113) is different in the groove width direction.

The invention discloses a stator punching sheet, a motor and a compressor, and relates to the technical field of motors, the stator punching sheet comprises a yoke part and a plurality of tooth parts, the plurality of tooth parts are arranged on the inner circumference of the yoke part at intervals, a stator slot is formed between two adjacent tooth parts, the plurality of stator slots comprise a plurality of first stator slots and a plurality of second stator slots, and the plurality of first stator slots and the plurality of second stator slots are arranged at intervals. The area of the first stator slot is larger than that of the second stator slot; wherein the distance between the first groove bottom and the center of the stator punching sheet is two times D1, the distance between the second groove bottom and the center of the stator punching sheet is two times D2, the groove width of each stator groove is W, the inner diameter of each tooth part is D3, D1 and D3 meet the condition that (D1-D3) / 2D3 is larger than or equal to 0.28 and smaller than or equal to 0.31, and W and D3 meet the condition that W / D3 is larger than or equal to 0.136 and smaller than or equal to 0.142. According to the technical scheme, the sizes of the stator punching sheet and the stator grooves are reasonably designed, so that the motor efficiency of the motor with the stator punching sheet is improved, the heating value of the motor is reduced, and the reliability and the stability of the motor in the operation process are improved.

To improve traction performance while securing heat build-up resistance.SOLUTION: Groove widths of narrow grooves 21, 22 and 41 with respect to groove depths thereof are 10[%] or more and 25[%] or less. Center blocks 31A have protruding parts 31Ab formed so that either of the parts adjacent to each other in a tire width direction protrudes toward the other. The protruding parts are arranged so that the parts fit to a space between protruding parts of the other center blocks formed adjacently in a tire circumferential direction. Width-directional narrow grooves and shoulder lug groove 43 are arranged so that respective end parts 41a and 43a thereof oppose to each other. An angle θa1 of the shoulder lug groove with respect to the tire circumferential direction is 80[Deg] or more and less than 100 [Deg]. The width-directional narrow grooves are larger in inclination with respect to the tire width direction than the shoulder lug grooves. The number of shoulder blocks 32A arranged in the tire circumferential direction is 28 or more and 43 or less. In a tread part, a center tread gauge on a tire equatorial plane CL is 40[mm] or more, and a ratio of the center tread gauge with respect to groove depths of the shoulder lug grooves is 105[%] or more and 185[%] or less.SELECTED DRAWING: Figure 1

The utility model discloses groove-shaped plate processing equipment, and relates to the field of groove-shaped plate processing. Through the arrangement of the sliding groove, the sliding plate, the L-shaped plate and the pressing plate, under the action of the sliding groove, the L-shaped plate and the pressing plate can rotate, then the L-shaped plate and the pressing plate can flexibly and freely rotate, the rotating mechanism brings great convenience to plate machining, plates of various shapes and specifications can tightly lean against the L-shaped plate, and the machining efficiency is improved. Under the action of the rotating plate and the scales, the sliding plate rotates, the radian of the groove is accurately controlled, measurement errors are reduced, clear scale marks enable data reading to be simple and visual, working efficiency is improved, the device is used for positioning parts or tools, machining accuracy and precision are guaranteed, and the device is suitable for popularization and application. The grooving width is kept uniform, the construction quality is improved, the measurement and adjustment time is shortened, meanwhile, the structural stability is enhanced, and the convenience and safety of the plate in the grooving process are improved.

The application discloses a joint structure of high-energy beam welding and a processing and welding method thereof, and aims at solving the problems of stress concentration, gas residue, heat affected zone and difficult control of welding quality in the prior art. The joint structure comprises coaxially assembled base material I and base material II; a first annular groove is arranged on a welding surface of the base material I, a second annular groove is arranged on a welding surface of the base material II, the groove widths of the first annular groove and the second annular groove are consistent and the positions of the first annular groove and the second annular groove correspond; the first annular groove and the second annular groove form an annular stress relief channel after the base material I and the base material II are assembled; at least one exhaust channel is arranged on the base material I and / or the base material II, one end of the exhaust channel is communicated with the annular stress relief channel, and the other end is used for communicating with an external environment; and the maximum radial dimension of the communicated position of the exhaust channel and the annular stress relief channel is smaller than the groove width of the annular stress relief channel. The structure can eliminate stress concentration during welding, and prevent the initiation and expansion of cracks after welding.

The utility model discloses an active and passive annular locking plate self-ligating bracket, which comprises a bracket matrix provided with an arch wire groove, and further comprises an annular locking plate provided with an arc section and a concave section which are connected in sequence to form an annular structure with an opening, and an annular locking plate provided with an arc section and a concave section which are connected in sequence to form an annular structure with an opening, an annular groove is further formed in the portion, on the periphery of the arch wire groove, of the parent body, the annular groove is provided with a first annular groove opening, a second annular groove opening and an annular groove first transition section, and the groove width of the annular groove first transition section is larger than that of other portions of the annular groove. And the annular locking plate can rotate in the annular groove. The bracket disclosed by the utility model has the advantages that the bracket is simple in structure and convenient to lock, and active self-locking and passive self-locking can be realized at the same time.

A tread for a vehicle tire, wherein a profile groove (1) with a radially upper region (2) and a radially lower region (3) and with two groove flanks (4, 5) is formed in the tread, wherein in the radially upper region (2) of the profile groove (1) lateral overhangs (6) are formed on the groove flanks (4, 5) such that a groove width (7) in the radially upper region (2) is smaller than in the radially lower region (3), wherein the profile groove (1) assumes a zigzag and / or curved shape in the radially upper region (2) and a straight shape in the radially lower region (3). Viewed in a cross-sectional area perpendicular to the longitudinal extent of the profile groove (1), the radially lower region (3) is asymmetric with respect to one radial direction.

A cathode plate insulation edge clamping strip for electrolysis comprises a clamping groove for clamping a cathode plate and a circular groove for containing an expansion rod, the directions of groove openings of the clamping groove and the circular groove are opposite, the clamping groove is a straight groove, the range of a groove cavity of the circular groove is larger than a semicircle, the clamping groove and the circular groove share a groove bottom, and symmetric planes in the groove width direction of the clamping groove and the circular groove are coplanar; the whole groove wall of the groove bottom section of the clamping groove is an equal-thickness groove wall, the groove wall of the groove middle section of the clamping groove is gradually and slowly thinned from the groove cavity to the groove wall of the groove opening, and the groove wall of the groove opening section of the clamping groove is sharply thinned from the groove cavity to the groove opening; the whole groove wall of the circular groove is equal in thickness; the joint of the outer wall face of the groove wall of the circular groove and the outer wall face of the groove bottom section groove wall and the outer wall face of the groove middle section groove wall of the clamping groove smoothly extends in an inwards-concave mode. According to the technical scheme, the stability and reliability of tightly clamping the negative plate by the edge clamping strip are improved, the smoothness of the edges of the two sides of a finished product plate obtained through electrolysis is improved, and electrolysis flaws are reduced.

The utility model discloses an automatic chamfering tool for bars, which is characterized by comprising a chain wheel, a baffle plate, a chamfering grinding wheel and an automatic feeding device, the chain wheel is provided with a plurality of grooves for placing the bars, the baffle plate is arranged on the outer side of the revolution surface of the chain wheel, the chain wheel and the chamfering grinding wheel are coaxially arranged, and the automatic feeding device is arranged on one side of the baffle plate. By means of the ingeniously-designed combination of the crankset and the baffle, stable rotation and uniform rolling of bars in the machining process are achieved, and therefore the uniformity of the roundness and the width of chamfers is guaranteed. The thickness and the groove width of the crankset can be flexibly adjusted according to the size of the bar, and the machining precision and applicability are further improved.

A firestarter includes an integral block of wood of six sides. A slat and groove portion extends from an outermost bottom surface of a bottom side towards a top wall of the top side. The slat and groove portion includes a plurality of slats and a plurality of grooves. Each slat of the plurality of slats has a slat width and each groove of the plurality of grooves has a groove width. The slat width and the groove width are the same. The plurality of grooves extend through the front side, the back side and the bottom side and the plurality of grooves do not extend through the first side, the second side, and the top side.

The invention discloses an equal-groove-width variable-pitch engineering tire pattern structure giving consideration to low noise and full abrasion period equal saturation, and relates to the technical field of tires. The technical bottlenecks of single performance, inconsistent performance of each pitch, uneven abrasion, poor structural reliability and low universality in the variable pitch design of the traditional engineering tire are broken through, and through the integrated innovative design of the equal-groove-width foundation design, the density differentiation matrix solid salient points and the third-order universal pitch proportion, the variable pitch design of the engineering tire is achieved. The low noise, the performance consistency, the uniform abrasion and the structural reliability are synergistically considered, and the use requirements of heavy load and multiple working conditions of the engineering tire are comprehensively met.

The present disclosure relates to a tire in which: a meandering groove extending in a tire circumferential direction is formed on a tread surface; a groove width of the meandering groove in a tire width direction varies along the tire circumferential direction at a predetermined repeating cycle; a ratio Wmin / Wmax of a maximum width and a minimum width of the groove width is 0.35 to 0.85; a first groove wall and a second groove wall, which are two groove walls of the meandering groove, each extend in a sinusoidal meandering manner in a tread surface view with the predetermined repeating cycle as a cycle length; and a first sinusoidal curve formed by the first groove wall and a second sinusoidal curve formed by the second groove wall are arranged with a phase difference of 1 / 8 to 3 / 8 of a cycle in the tire circumferential direction in the tread surface view.

The invention belongs to the technical field of machining, and particularly relates to a process control method for the axial linear size of an inner groove of a micro part. Comprising the steps that 1, an inner hole and an end face on the opposite side of a control edge of an inner groove are machined to theoretical sizes; 2, machining an inner hole in the corresponding side of the control edge of the inner groove to a first size, wherein the first size is obtained by subtracting the first value b from the theoretical value; 3, determining a tool nose fillet R; 4, machining the inner hole in the corresponding side of the control edge to a first size by adopting a tool nose with a fillet R; 5, machining the inner groove to a first groove width by using a tool nose with a fillet R, wherein the inner groove and the inner hole on the corresponding side of the control edge form a measuring surface; step 6, measuring the distance from the end face on the opposite side of the control side to the measurement surface by using a depth micrometer; and 7, under the condition that the distance meets the threshold value, an inner hole in the side corresponding to the control edge of the inner groove is machined to the theoretical size through a tool nose with a fillet R, and the width of the inner groove is changed into the theoretical groove width from the first groove width at the moment.

The utility model discloses a simple piston ring with oil storage grooves, which comprises a ring-shaped main body structure and is characterized in that a plurality of oil storage grooves are processed and formed on an excircle working surface of the ring-shaped main body structure by adopting a milling or grinding process, the plurality of oil storage grooves are annular and are uniformly distributed along the axial direction, the groove width of each oil storage groove is 0.5 mm, and the groove width of each oil storage groove is 0.5 mm. The depth of the oil storage grooves is 0.2 mm, and the sum of the widths of the oil storage grooves accounts for 1 / 3-1 / 2 of the height of the annular body structure. The lubricating device is simple in structure and good in lubricating effect.

A tyre (1) comprises a tread band (2) in a radially outer position, on which a tread surface (3) is defined. The aforementioned tread band (2) comprises a plurality of grooves (7A, 7B), each groove comprising a first wall (71) and a second wall (72) facing each other and defining a groove width (WG). At least one of the first wall (71) and the second wall (72) comprises a plurality of protrusions (8) protruding from at least one of the first wall (71) and the second wall (72), having a protrusion width (WP), where the protrusion width (WP) is less than 20% of the groove width (WG).

This invention discloses an online tool health monitoring method and system based on workpiece machining quality data fusion. First, the deviation between the actual groove width and the standard groove width of the workpiece is calculated, constructing a time-series sequence of groove width deviation. Then, a sliding time window mechanism is used to dynamically extract multi-dimensional time-series features, including mean, standard deviation, slope, out-of-tolerance count, and previous values, comprehensively characterizing the nonlinear evolution trend during tool wear. Further, the fused feature vector can be input into a random forest regression model to achieve high-precision prediction of the current groove width. Finally, based on the deviation between the predicted groove width and the standard groove width, the tool degradation state is evaluated in real time. This invention directly utilizes groove width data from the machining process, eliminating the need for additional sensor deployment. It offers advantages such as low cost, high reliability, and strong real-time performance, reducing scrap rate and improving tool life without increasing hardware investment.

The utility model provides a pipeline supporting device, and relates to the technical field of pipeline erection. In the device, a positioning part for positioning a pipeline is arranged at the upper end of a supporting seat, and the lower end of the supporting seat is supported on a plurality of base plate units which are distributed at intervals; at least one of the base plate units comprises a plurality of base plates stacked in the vertical direction, at least one of the base plate units is a set base plate unit, the base plates of the set base plate unit comprise a first base plate and a second base plate, and the adjacent end faces of the first base plate and the second base plate in the vertical direction are matched slopes. The first base plate and the second base plate are respectively provided with a groove and a boss at the inclined surface; the groove and the boss extend in the first horizontal direction, and the first horizontal direction is perpendicular to the inclination direction of the inclined face. The boss and the adjusting unit are contained in the groove, the adjusting unit comprises a plurality of adjusting blocks, the boss is provided with the adjusting blocks on the set side in the groove width direction of the groove, and the set side is the side, close to the lower end of the slope, of the boss in the groove width direction.

Task To provide a tire that can provide resistance to uneven wear and performance on snow in a compatible manner. Solution: A plurality of circumferential grooves (20) arranged in a tread surface (15A) includes a pair of outermost circumferential grooves (21) arranged on respective outermost sides in the tire width direction, and a narrow circumferential groove (22) having a groove width of 30% or less of a groove width of the outermost circumferential grooves (21). A central portion (31) has a width (CW) of 45% or more of a development width (TW) in the tire width direction. A lug groove (40) includes a closed lug groove (40a) that closes on one side of the groove bottom (40ab) from a position of at least half a groove depth (Dc) during ground contact, and an open lug groove (40b) that does not close during ground contact.A block (30) includes central blocks (31Ba) defined by the circumferential grooves (20) arranged on an inner side in the tire width direction of each of the outermost circumferential grooves (21). In a central block row (31B) in which the central blocks (31Ba) are arranged in the tire circumferential direction, the closed lug groove (40a) and the open lug groove (40b) are arranged alternately in the tire circumferential direction.

A tire (2) according to the present application can reduce the rolling resistance without reducing the WET performance. The tire (2) includes a tread (4) and a belt layer (14). The belt layer (14) includes an inner layer (38) and an outer layer (40). An end portion of the outer layer (40) is located axially inward of an end portion of the inner layer (38). A circumferential fine groove (48) extending continuously in the circumferential direction is formed in a shoulder land portion (46s). A groove width of the circumferential fine groove (48) is narrower than a groove width of a shoulder circumferential groove (44s). The circumferential fine groove (48) is located axially between the shoulder circumferential groove (44s) and the end portion of the outer layer (40). A ratio of an axial distance from the shoulder circumferential groove (44s) to the circumferential fine groove (48) to an axial distance from the shoulder circumferential groove (44s) to the end portion of the outer layer (40) is 15% or more and 55% or less.

The utility model provides a quartz boat and wafer processing equipment, and relates to the technical field of semiconductors. A first groove rod, a second groove rod, a third groove rod and a fourth groove rod of the quartz boat are arranged in parallel, the first groove rod and the second groove rod are located above the third groove rod and the fourth groove rod, and the projection of the third groove rod and the projection of the fourth groove rod on the horizontal plane are located between the projection of the first groove rod and the projection of the second groove rod on the horizontal plane. Two ends of the first groove rod, the second groove rod, the third groove rod and the fourth groove rod are respectively connected with the first side plate and the second side plate; wherein the inner side surfaces of the first groove rod and the second groove rod are provided with V-shaped grooves, the inner side surfaces of the third groove rod and the fourth groove rod are provided with flat-bottom grooves, and the groove widths of the V-shaped grooves and the flat-bottom grooves are greater than the width of a wafer; when the wafer is placed in the quartz boat, the wafer abuts against the bottom of the flat bottom groove and the side wall of the V-shaped groove. The method has the advantage of improving the integrity of a wafer product.

The utility model discloses an opening and closing adjusting assembly for an ice detection arm of an ice machine and the ice machine. The opening and closing adjusting assembly comprises a lock catch, a locking mechanism and a locking mechanism, wherein the lock catch is suitable for being in sliding fit with a shell of the ice machine; the lock catch at least comprises a shifting plate, and a sliding guide structure and a sliding locking structure which are formed between the shifting plate and a matching surface of a shell of the ice maker; the sliding locking structure comprises a locking groove and a locking cap which are matched in an inserted mode. The locking groove comprises a straight groove part extending in the sliding direction of the lock catch and a pair of groove end heads arranged at the two side ends of the straight groove part and matched with the locking cap. The groove width and / or the groove depth of the straight groove part perpendicular to the movement direction of the lock catch are / is smaller than the groove width and / or the groove depth of any groove end; when the ice detection arm is in a locking state, the locking cap is located in one groove end of the locking groove, and when the ice detection arm is in a starting state, the locking cap is located in the other groove end of the locking groove. According to the utility model, the accuracy of adjusting the motion state of the ice detection arm by the lock catch motion can be improved.

Profile system (1) comprising at least one elongated rail profile (2) extending in a longitudinal direction (L) and having a constant cross-section, and at least one retaining element (3) designed to be detachably attached to the rail profile (2), wherein the rail profile (2) in cross-section has a substantially rectangular base section (6) provided on its front face with a receiving groove (7) extending in the longitudinal direction (L) which describes a circular arc (8) extending over at least 200° with a first radius R1 and is accessible via a groove opening (9) of a predetermined groove width (B), and at least one first fastening leg (13) which is substantially flush with the rear face of the base section (6) and projects outwards from the base section (6), and wherein the retaining element (3) comprises a retaining section (15) and a retaining element (15) attached thereto.a connecting section (16) elongated and extending in the longitudinal direction (L), wherein the connecting section (16) comprises at least a web (17) extending outwards from the retaining section (15) and a cylindrically shaped joint head (18) arranged at the free end of the web (17), the lateral surface of which, viewed in cross-section, describes a circular arc with radius R2 equal to or slightly smaller than radius R1, wherein the maximum distance (a, max) between a circular chord (19) bounding the circular arc and the lateral surface is slightly smaller than the groove width (B), so that the rod end (18) can be inserted through the groove opening (9) into the receiving groove (7) in a certain pivot position of the retaining element (3) with respect to a pivot axis (20) extending in the longitudinal direction (L) and can be locked within the receiving groove (7) during a pivoting movement about the pivot axis (20), characterized in that the web (17) of the connecting section (16) projects from the retaining section (15) at an angle (β) in the range between 100° and 110°.

The present disclosure provides a body comprising an insert pocket into which a cutting insert is mounted, the insert pocket including: a lower jaw part having a screw hole; an upper jaw part that is arranged apart from the lower jaw part; and a housing groove part into which the cutting insert is inserted, the housing groove part being formed between the lower jaw part and the upper jaw part, wherein the housing groove part is formed such that a groove width on a leading end side is narrower than a groove width on a rear end side

To provide a tire that can exert excellent braking performance on a dry road surface while maintaining on-ice performance.SOLUTION: The present invention pertains to a tire including a tread portion 2. The tread portion 2 includes a first shoulder circumferential groove 5 and a first shoulder land portion 11. Shoulder lateral grooves 15 disposed in the first shoulder land portion 11 include a plurality of outer shoulder lateral grooves 16 and a plurality of inner shoulder lateral grooves 17. Each of the plurality of outer shoulder lateral grooves 16 includes: a minimum portion 21 having a minimum groove width; and a maximum portion 22 disposed on a radially inward of the minimum portion 21 and having a groove width larger than the minimum portion. Each of the plurality of inner shoulder lateral grooves 17 has a groove width continuously decreasing from an opening portion 17a to a groove bottom portion 17b or a groove width constant from the opening portion 17a to the groove bottom portion 17b.SELECTED DRAWING: Figure 1

To provide a tire capable of further improving snow performance.SOLUTION: In a tire including a plurality of lug grooves 10 extending in a tire radial direction from a tread portion 1 toward a sidewall portion 2, a plurality of shoulder blocks 21 defined in a shoulder region by the lug grooves 10, and a plurality of side blocks 22 defined in a side region by the lug grooves 10, the plurality of lug grooves 10 include a first lug groove 11 and a second lug groove 12 alternately arranged along a tire circumferential direction, and the first lug groove 11 includes a first widened portion side 11A having a locally widened groove. The second lug grooves 12 each have a second widened portion side 12A where the groove is locally widened, and the positions of the first widened portion side 11A and the second widened portion side 12A in the tire radial direction are different from each other.SELECTED DRAWING: Figure 2

To provide a pneumatic tire which can reduce air column resonance sound while suppressing deterioration of contact area at the time of new one.SOLUTION: A pneumatic tire arranges a plurality of resonators 4 including on a land part 3 partitioned between a first circumferential direction main groove 2a and a second circumferential direction main groove 2b adjacent to the first circumferential direction main groove in a tire width direction: sub grooves which are terminated in the land part; and branch grooves which communicate with the sub grooves and the circumferential main grooves. The branch groove includes: a first branch groove which communicates an end of the sub groove at one side in a tire circumferential direction with the first circumferential main groove; and a second branch groove which communicates an end of the sub groove at the other side in the tire circumferential direction with the second circumferential main groove. An expanded width part whose groove width is larger than that at an opening part on a tread surface 1 is formed at at least a part in a groove depth direction of the sub groove at a portion that is at least a part in an extension direction of the sub groove. An extension length of the first branch groove and an extension length of the second branch groove are respectively longer than length of the sub groove in the tire circumferential direction.SELECTED DRAWING: Figure 1